3. Spline Drive This article explains the design differences between these systems, and it explains why knowing a power hammer's chuck system design is the key to getting a compatible bit for that hammer.   Match the Bit Type to the Chuck System To find a compatible bit for your hammer drill or rotary hammer, you only need to know one thing: the chuck system (SDS/SDS-Plus, SDS Max, or Spline). It's that simple. Although there are other bit type considerations when making a purchase, as far as making sure that the bit shank will fit the hammer chuck, matching it to the chuck system is the one and only step. This is because the type of chuck system completely determines two things: 1. The diameter of the bit shank (the end of the drill bit that fits into the chuck), and 2. The number and type of grooves/keyways on the bit shank that fit into the innards of the chuck.   So, for example, any of the SDS-Plus bits pictured below (despite their differing bit diameter, length, and other features) will fit perfectly into any SDS/SDS-Plus chuck system, because their shank diameters are the same, and the number/placement of their grooves are the same. Comparably, any SDS MAX or Spline bit will also fit perfectly into any tool with a matching chuck system. (SDS and SDS-Plus are the only cross-compatible bit systems, making the terms interchangeable.) Here's the catch: Hammer drill and rotary hammer owners must know which chuck system their tool uses. The type of chuck system cannot be determined by simply looking at the chuck, probing its opening with a finger, or by any other means. Tools that use these systems will almost always be advertised with the name of the chuck system as part of the tool's advertised name. However, because a tool model number always corresponds to only one kind of chuck system, model numbers are used to pinpoint the exact tool (chuck system included) after sale. Also, the name of the chuck system may be written on the tool somewhere and can always be found in the user manual. The point is that if the chuck system isn't already known, then the tool's model number must be known in most cases to find out which system it uses. Example: The Bosch 11224VSR Hammer Drill uses an SDS-Plus system, and probably included that information in its advertised name. But, like its title on our parts page for this tool, chuck system details are usually omitted from a tool's title after sale, since the model number is included in the title and is the surest way of leading to accurate information concerning the tool.   If you have the model number of your tool but aren't sure about which chuck design it uses, try the following: Look up what the chuck system is in the user manual (often available online at manufacturer websites), or look for it written on the tool somewhere. If a manual isn't available, use the model number of the tool in a broad internet search to find out the tool's specifics. Look closely at an old bit. The chuck system to which it corresponds is almost always engraved somewhere on the hardware. If the above resources are not available or don't produce the needed information, simply try fitting the different types of bits into the chuck (SDS/SDS-plus, SDS Max, and Spline). The tool might need to be taken somewhere where hammer bits are sold for this test, if the variety of needed bits is not available otherwise. The correct bit is the only one that will fit into the chuck. After matching the right bit design to its mirror chuck system, other factors that determine bit type can be explored from there (bits for chiseling, cutting, digging, chipping, etc.) to match user preference and application. Below is a detailed description for each of the three chuck systems. [Back to top]   SDS/SDS-Plus, SDS Max, and Spline Chuck Systems Explained "Since they can be tough to keep separate, why the different chuck systems?" That's a fair question. Bosch developed the first SDS system back in 1975. In English-speaking markets, SDS stands for "Special Direct System." SDS chuck systems are specially adapted for concrete and other masonry hammering. In hammers that use traditional chucks, the striking piston uses part of its energy to move the heavy chuck piece back and forth, as well as the drill bit. In an SDS system, the flat end of the drill bit is the only thing that the piston hits and has to move. This makes its energy usage more direct, efficient, and effective. Also, the grooves in an SDS bit shank allow the bit to slide back and forth when it is hit by the piston, providing even more potential for the bit to be accelerated efficiently by the energy of the piston. The snappiest feature of the SDS systems is probably their one-hand bit changing. Inside each SDS chuck there are spring-loaded balls designed to fit into the grooves of SDS bit shanks. After being inserted into the chuck, an SDS bit just needs a little twist for those balls to snap into place and hold the drill bit. In German markets, SDS stands for "Steck, Dreh, Sitz" (Insert, Twist, Stay). Cool, huh? And those are the major benefits of SDS systems. Spline drive bits and chucks are an older system that, like the SDS Max system, is designed with the above features in mind, but for the most heavy-duty masonry drilling; although, SDS Max systems include some advantages over Spline systems.     When Bosch introduced the first SDS system, it was simply called SDS. Later, improvements were made that helped the shank design hold more firmly, and the design changes were dubbed "SDS-Plus." However, the improvements did not have any impact on compatibility, so SDS and SDS-Plus are interchangeable in both terminology and function. For new tools, SDS-Plus (sometimes written "SDS+") has simply replaced SDS. SDS-Plus bit shanks have four indentions on them: two that are open-ended, and two that are close-ended (which keep the bit from flying out of the chuck). The SDS-Plus icon above shows a top view of an SDS-Plus shank, and depicts the orientation of its four grooves. Also, see the picture below for side views of SDS-Plus shanks:   SDS-Plus systems are the most common, since they're adapted for relatively less-heavy drilling (in comparison to larger hammer drills), and their shanks have a diameter of 10mm. [Back to top]     SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

There are three main types of hardness measurements: scratch, indentation, and rebound. Within each of these classes of measurement there are individual measurement scales. For practical reasons conversion tables are used to convert between one scale and another.

Hardness of steel depends onmcq

There are two types of irregularities at the grain level of the microstructure that are responsible for the hardness of the material. These irregularities are point defects and line defects. A point defect is an irregularity located at a single lattice site inside of the overall three-dimensional lattice of the grain. There are three main point defects. If there is an atom missing from the array, a vacancy defect is formed. If there is a different type of atom at the lattice site that should normally be occupied by a metal atom, a substitutional defect is formed. If there exists an atom in a site where there should normally not be, an interstitial defect is formed. This is possible because space exists between atoms in a crystal lattice. While point defects are irregularities at a single site in the crystal lattice, line defects are irregularities on a plane of atoms. Dislocations are a type of line defect involving the misalignment of these planes. In the case of an edge dislocation, a half plane of atoms is wedged between two planes of atoms. In the case of a screw dislocation two planes of atoms are offset with a helical array running between them.[8]

The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation, such as an indentation (over an area) or a scratch (linear), induced mechanically either by pressing or abrasion. In general, different materials differ in their hardness; for example hard metals such as titanium and beryllium are harder than soft metals such as sodium and metallic tin, or wood and common plastics. Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, hardness can be measured in different ways, such as scratch hardness, indentation hardness, and rebound hardness. Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. Common examples of hard matter are ceramics, concrete, certain metals, and superhard materials, which can be contrasted with soft matter.

The key to understanding the mechanism behind hardness is understanding the metallic microstructure, or the structure and arrangement of the atoms at the atomic level. In fact, most important metallic properties critical to the manufacturing of today’s goods are determined by the microstructure of a material.[7] At the atomic level, the atoms in a metal are arranged in an orderly three-dimensional array called a crystal lattice. In reality, however, a given specimen of a metal likely never contains a consistent single crystal lattice. A given sample of metal will contain many grains, with each grain having a fairly consistent array pattern. At an even smaller scale, each grain contains irregularities.

Mildsteel hardnessRockwell C

Careful note should be taken of the relationship between a hardness number and the stress-strain curve exhibited by the material. The latter, which is conventionally obtained via tensile testing, captures the full plasticity response of the material (which is in most cases a metal). It is in fact a dependence of the (true) von Mises plastic strain on the (true) von Mises stress, but this is readily obtained from a nominal stress – nominal strain curve (in the pre-necking regime), which is the immediate outcome of a tensile test. This relationship can be used to describe how the material will respond to almost any loading situation, often by using the Finite Element Method (FEM). This applies to the outcome of an indentation test (with a given size and shape of indenter, and a given applied load).

SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

In glasses, hardness seems to depend linearly on the number of topological constraints acting between the atoms of the network.[9] Hence, the rigidity theory has allowed predicting hardness values with respect to composition.

There are five hardening processes: Hall-Petch strengthening, work hardening, solid solution strengthening, precipitation hardening, and martensitic transformation.

Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

thehardness of steelincreases if it contains ans. pearlite martensite cementite austenite

When Bosch introduced the first SDS system, it was simply called SDS. Later, improvements were made that helped the shank design hold more firmly, and the design changes were dubbed "SDS-Plus." However, the improvements did not have any impact on compatibility, so SDS and SDS-Plus are interchangeable in both terminology and function. For new tools, SDS-Plus (sometimes written "SDS+") has simply replaced SDS. SDS-Plus bit shanks have four indentions on them: two that are open-ended, and two that are close-ended (which keep the bit from flying out of the chuck). The SDS-Plus icon above shows a top view of an SDS-Plus shank, and depicts the orientation of its four grooves. Also, see the picture below for side views of SDS-Plus shanks:   SDS-Plus systems are the most common, since they're adapted for relatively less-heavy drilling (in comparison to larger hammer drills), and their shanks have a diameter of 10mm. [Back to top]     SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

SDS-Plus systems are the most common, since they're adapted for relatively less-heavy drilling (in comparison to larger hammer drills), and their shanks have a diameter of 10mm. [Back to top]     SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

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Hardness increases with decreasing particle size. This is known as the Hall-Petch relationship. However, below a critical grain-size, hardness decreases with decreasing grain size. This is known as the inverse Hall-Petch effect.

SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

2. SDS Max, and 3. Spline Drive This article explains the design differences between these systems, and it explains why knowing a power hammer's chuck system design is the key to getting a compatible bit for that hammer.   Match the Bit Type to the Chuck System To find a compatible bit for your hammer drill or rotary hammer, you only need to know one thing: the chuck system (SDS/SDS-Plus, SDS Max, or Spline). It's that simple. Although there are other bit type considerations when making a purchase, as far as making sure that the bit shank will fit the hammer chuck, matching it to the chuck system is the one and only step. This is because the type of chuck system completely determines two things: 1. The diameter of the bit shank (the end of the drill bit that fits into the chuck), and 2. The number and type of grooves/keyways on the bit shank that fit into the innards of the chuck.   So, for example, any of the SDS-Plus bits pictured below (despite their differing bit diameter, length, and other features) will fit perfectly into any SDS/SDS-Plus chuck system, because their shank diameters are the same, and the number/placement of their grooves are the same. Comparably, any SDS MAX or Spline bit will also fit perfectly into any tool with a matching chuck system. (SDS and SDS-Plus are the only cross-compatible bit systems, making the terms interchangeable.) Here's the catch: Hammer drill and rotary hammer owners must know which chuck system their tool uses. The type of chuck system cannot be determined by simply looking at the chuck, probing its opening with a finger, or by any other means. Tools that use these systems will almost always be advertised with the name of the chuck system as part of the tool's advertised name. However, because a tool model number always corresponds to only one kind of chuck system, model numbers are used to pinpoint the exact tool (chuck system included) after sale. Also, the name of the chuck system may be written on the tool somewhere and can always be found in the user manual. The point is that if the chuck system isn't already known, then the tool's model number must be known in most cases to find out which system it uses. Example: The Bosch 11224VSR Hammer Drill uses an SDS-Plus system, and probably included that information in its advertised name. But, like its title on our parts page for this tool, chuck system details are usually omitted from a tool's title after sale, since the model number is included in the title and is the surest way of leading to accurate information concerning the tool.   If you have the model number of your tool but aren't sure about which chuck design it uses, try the following: Look up what the chuck system is in the user manual (often available online at manufacturer websites), or look for it written on the tool somewhere. If a manual isn't available, use the model number of the tool in a broad internet search to find out the tool's specifics. Look closely at an old bit. The chuck system to which it corresponds is almost always engraved somewhere on the hardware. If the above resources are not available or don't produce the needed information, simply try fitting the different types of bits into the chuck (SDS/SDS-plus, SDS Max, and Spline). The tool might need to be taken somewhere where hammer bits are sold for this test, if the variety of needed bits is not available otherwise. The correct bit is the only one that will fit into the chuck. After matching the right bit design to its mirror chuck system, other factors that determine bit type can be explored from there (bits for chiseling, cutting, digging, chipping, etc.) to match user preference and application. Below is a detailed description for each of the three chuck systems. [Back to top]   SDS/SDS-Plus, SDS Max, and Spline Chuck Systems Explained "Since they can be tough to keep separate, why the different chuck systems?" That's a fair question. Bosch developed the first SDS system back in 1975. In English-speaking markets, SDS stands for "Special Direct System." SDS chuck systems are specially adapted for concrete and other masonry hammering. In hammers that use traditional chucks, the striking piston uses part of its energy to move the heavy chuck piece back and forth, as well as the drill bit. In an SDS system, the flat end of the drill bit is the only thing that the piston hits and has to move. This makes its energy usage more direct, efficient, and effective. Also, the grooves in an SDS bit shank allow the bit to slide back and forth when it is hit by the piston, providing even more potential for the bit to be accelerated efficiently by the energy of the piston. The snappiest feature of the SDS systems is probably their one-hand bit changing. Inside each SDS chuck there are spring-loaded balls designed to fit into the grooves of SDS bit shanks. After being inserted into the chuck, an SDS bit just needs a little twist for those balls to snap into place and hold the drill bit. In German markets, SDS stands for "Steck, Dreh, Sitz" (Insert, Twist, Stay). Cool, huh? And those are the major benefits of SDS systems. Spline drive bits and chucks are an older system that, like the SDS Max system, is designed with the above features in mind, but for the most heavy-duty masonry drilling; although, SDS Max systems include some advantages over Spline systems.     When Bosch introduced the first SDS system, it was simply called SDS. Later, improvements were made that helped the shank design hold more firmly, and the design changes were dubbed "SDS-Plus." However, the improvements did not have any impact on compatibility, so SDS and SDS-Plus are interchangeable in both terminology and function. For new tools, SDS-Plus (sometimes written "SDS+") has simply replaced SDS. SDS-Plus bit shanks have four indentions on them: two that are open-ended, and two that are close-ended (which keep the bit from flying out of the chuck). The SDS-Plus icon above shows a top view of an SDS-Plus shank, and depicts the orientation of its four grooves. Also, see the picture below for side views of SDS-Plus shanks:   SDS-Plus systems are the most common, since they're adapted for relatively less-heavy drilling (in comparison to larger hammer drills), and their shanks have a diameter of 10mm. [Back to top]     SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

Scratch hardness is the measure of how resistant a sample is to fracture or permanent plastic deformation due to friction from a sharp object.[1] The principle is that an object made of a harder material will scratch an object made of a softer material. When testing coatings, scratch hardness refers to the force necessary to cut through the film to the substrate. The most common test is Mohs scale, which is used in mineralogy. One tool to make this measurement is the sclerometer.

Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

Hardness of steelMohs

Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

When Bosch introduced the first SDS system, it was simply called SDS. Later, improvements were made that helped the shank design hold more firmly, and the design changes were dubbed "SDS-Plus." However, the improvements did not have any impact on compatibility, so SDS and SDS-Plus are interchangeable in both terminology and function. For new tools, SDS-Plus (sometimes written "SDS+") has simply replaced SDS. SDS-Plus bit shanks have four indentions on them: two that are open-ended, and two that are close-ended (which keep the bit from flying out of the chuck). The SDS-Plus icon above shows a top view of an SDS-Plus shank, and depicts the orientation of its four grooves. Also, see the picture below for side views of SDS-Plus shanks:   SDS-Plus systems are the most common, since they're adapted for relatively less-heavy drilling (in comparison to larger hammer drills), and their shanks have a diameter of 10mm. [Back to top]     SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

Another tool used to make these tests is the pocket hardness tester. This tool consists of a scale arm with graduated markings attached to a four-wheeled carriage. A scratch tool with a sharp rim is mounted at a predetermined angle to the testing surface. In order to use it a weight of known mass is added to the scale arm at one of the graduated markings, the tool is then drawn across the test surface. The use of the weight and markings allows a known pressure to be applied without the need for complicated machinery.[2]

Hammer drill and rotary hammer owners must know which chuck system their tool uses. The type of chuck system cannot be determined by simply looking at the chuck, probing its opening with a finger, or by any other means. Tools that use these systems will almost always be advertised with the name of the chuck system as part of the tool's advertised name. However, because a tool model number always corresponds to only one kind of chuck system, model numbers are used to pinpoint the exact tool (chuck system included) after sale. Also, the name of the chuck system may be written on the tool somewhere and can always be found in the user manual. The point is that if the chuck system isn't already known, then the tool's model number must be known in most cases to find out which system it uses. Example: The Bosch 11224VSR Hammer Drill uses an SDS-Plus system, and probably included that information in its advertised name. But, like its title on our parts page for this tool, chuck system details are usually omitted from a tool's title after sale, since the model number is included in the title and is the surest way of leading to accurate information concerning the tool.   If you have the model number of your tool but aren't sure about which chuck design it uses, try the following: Look up what the chuck system is in the user manual (often available online at manufacturer websites), or look for it written on the tool somewhere. If a manual isn't available, use the model number of the tool in a broad internet search to find out the tool's specifics. Look closely at an old bit. The chuck system to which it corresponds is almost always engraved somewhere on the hardware. If the above resources are not available or don't produce the needed information, simply try fitting the different types of bits into the chuck (SDS/SDS-plus, SDS Max, and Spline). The tool might need to be taken somewhere where hammer bits are sold for this test, if the variety of needed bits is not available otherwise. The correct bit is the only one that will fit into the chuck. After matching the right bit design to its mirror chuck system, other factors that determine bit type can be explored from there (bits for chiseling, cutting, digging, chipping, etc.) to match user preference and application. Below is a detailed description for each of the three chuck systems. [Back to top]   SDS/SDS-Plus, SDS Max, and Spline Chuck Systems Explained "Since they can be tough to keep separate, why the different chuck systems?" That's a fair question. Bosch developed the first SDS system back in 1975. In English-speaking markets, SDS stands for "Special Direct System." SDS chuck systems are specially adapted for concrete and other masonry hammering. In hammers that use traditional chucks, the striking piston uses part of its energy to move the heavy chuck piece back and forth, as well as the drill bit. In an SDS system, the flat end of the drill bit is the only thing that the piston hits and has to move. This makes its energy usage more direct, efficient, and effective. Also, the grooves in an SDS bit shank allow the bit to slide back and forth when it is hit by the piston, providing even more potential for the bit to be accelerated efficiently by the energy of the piston. The snappiest feature of the SDS systems is probably their one-hand bit changing. Inside each SDS chuck there are spring-loaded balls designed to fit into the grooves of SDS bit shanks. After being inserted into the chuck, an SDS bit just needs a little twist for those balls to snap into place and hold the drill bit. In German markets, SDS stands for "Steck, Dreh, Sitz" (Insert, Twist, Stay). Cool, huh? And those are the major benefits of SDS systems. Spline drive bits and chucks are an older system that, like the SDS Max system, is designed with the above features in mind, but for the most heavy-duty masonry drilling; although, SDS Max systems include some advantages over Spline systems.     When Bosch introduced the first SDS system, it was simply called SDS. Later, improvements were made that helped the shank design hold more firmly, and the design changes were dubbed "SDS-Plus." However, the improvements did not have any impact on compatibility, so SDS and SDS-Plus are interchangeable in both terminology and function. For new tools, SDS-Plus (sometimes written "SDS+") has simply replaced SDS. SDS-Plus bit shanks have four indentions on them: two that are open-ended, and two that are close-ended (which keep the bit from flying out of the chuck). The SDS-Plus icon above shows a top view of an SDS-Plus shank, and depicts the orientation of its four grooves. Also, see the picture below for side views of SDS-Plus shanks:   SDS-Plus systems are the most common, since they're adapted for relatively less-heavy drilling (in comparison to larger hammer drills), and their shanks have a diameter of 10mm. [Back to top]     SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

Hardness of steelincreases if it contains

Brittleness, in technical usage, is the tendency of a material to fracture with very little or no detectable plastic deformation beforehand. Thus in technical terms, a material can be both brittle and strong. In everyday usage "brittleness" usually refers to the tendency to fracture under a small amount of force, which exhibits both brittleness and a lack of strength (in the technical sense). For perfectly brittle materials, yield strength and ultimate strength are the same, because they do not experience detectable plastic deformation. The opposite of brittleness is ductility.

By varying the presence of interstitial atoms and the density of dislocations, a particular metal's hardness can be controlled. Although seemingly counter-intuitive, as the density of dislocations increases, there are more intersections created and consequently more anchor points. Similarly, as more interstitial atoms are added, more pinning points that impede the movements of dislocations are formed. As a result, the more anchor points added, the harder the material will become.

In solid mechanics, solids generally have three responses to force, depending on the amount of force and the type of material:

SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

Rebound hardness, also known as dynamic hardness, measures the height of the "bounce" of a diamond-tipped hammer dropped from a fixed height onto a material. This type of hardness is related to elasticity. The device used to take this measurement is known as a scleroscope.[3] Two scales that measures rebound hardness are the Leeb rebound hardness test and Bennett hardness scale. Ultrasonic Contact Impedance (UCI) method determines hardness by measuring the frequency of an oscillating rod. The rod consists of a metal shaft with vibrating element and a pyramid-shaped diamond mounted on one end.[4]

The most important factor in matching a bit to its hammer drill is knowing the chuck system of the tool, and choosing bits designed to correspond to that system. For hammer drills and rotary hammers, there are three major chuck/bit design systems available: 1. SDS/SDS-Plus (in terms of compatibility, "SDS" and "SDS-Plus" are completely interchangeable.) 2. SDS Max, and 3. Spline Drive This article explains the design differences between these systems, and it explains why knowing a power hammer's chuck system design is the key to getting a compatible bit for that hammer.   Match the Bit Type to the Chuck System To find a compatible bit for your hammer drill or rotary hammer, you only need to know one thing: the chuck system (SDS/SDS-Plus, SDS Max, or Spline). It's that simple. Although there are other bit type considerations when making a purchase, as far as making sure that the bit shank will fit the hammer chuck, matching it to the chuck system is the one and only step. This is because the type of chuck system completely determines two things: 1. The diameter of the bit shank (the end of the drill bit that fits into the chuck), and 2. The number and type of grooves/keyways on the bit shank that fit into the innards of the chuck.   So, for example, any of the SDS-Plus bits pictured below (despite their differing bit diameter, length, and other features) will fit perfectly into any SDS/SDS-Plus chuck system, because their shank diameters are the same, and the number/placement of their grooves are the same. Comparably, any SDS MAX or Spline bit will also fit perfectly into any tool with a matching chuck system. (SDS and SDS-Plus are the only cross-compatible bit systems, making the terms interchangeable.) Here's the catch: Hammer drill and rotary hammer owners must know which chuck system their tool uses. The type of chuck system cannot be determined by simply looking at the chuck, probing its opening with a finger, or by any other means. Tools that use these systems will almost always be advertised with the name of the chuck system as part of the tool's advertised name. However, because a tool model number always corresponds to only one kind of chuck system, model numbers are used to pinpoint the exact tool (chuck system included) after sale. Also, the name of the chuck system may be written on the tool somewhere and can always be found in the user manual. The point is that if the chuck system isn't already known, then the tool's model number must be known in most cases to find out which system it uses. Example: The Bosch 11224VSR Hammer Drill uses an SDS-Plus system, and probably included that information in its advertised name. But, like its title on our parts page for this tool, chuck system details are usually omitted from a tool's title after sale, since the model number is included in the title and is the surest way of leading to accurate information concerning the tool.   If you have the model number of your tool but aren't sure about which chuck design it uses, try the following: Look up what the chuck system is in the user manual (often available online at manufacturer websites), or look for it written on the tool somewhere. If a manual isn't available, use the model number of the tool in a broad internet search to find out the tool's specifics. Look closely at an old bit. The chuck system to which it corresponds is almost always engraved somewhere on the hardware. If the above resources are not available or don't produce the needed information, simply try fitting the different types of bits into the chuck (SDS/SDS-plus, SDS Max, and Spline). The tool might need to be taken somewhere where hammer bits are sold for this test, if the variety of needed bits is not available otherwise. The correct bit is the only one that will fit into the chuck. After matching the right bit design to its mirror chuck system, other factors that determine bit type can be explored from there (bits for chiseling, cutting, digging, chipping, etc.) to match user preference and application. Below is a detailed description for each of the three chuck systems. [Back to top]   SDS/SDS-Plus, SDS Max, and Spline Chuck Systems Explained "Since they can be tough to keep separate, why the different chuck systems?" That's a fair question. Bosch developed the first SDS system back in 1975. In English-speaking markets, SDS stands for "Special Direct System." SDS chuck systems are specially adapted for concrete and other masonry hammering. In hammers that use traditional chucks, the striking piston uses part of its energy to move the heavy chuck piece back and forth, as well as the drill bit. In an SDS system, the flat end of the drill bit is the only thing that the piston hits and has to move. This makes its energy usage more direct, efficient, and effective. Also, the grooves in an SDS bit shank allow the bit to slide back and forth when it is hit by the piston, providing even more potential for the bit to be accelerated efficiently by the energy of the piston. The snappiest feature of the SDS systems is probably their one-hand bit changing. Inside each SDS chuck there are spring-loaded balls designed to fit into the grooves of SDS bit shanks. After being inserted into the chuck, an SDS bit just needs a little twist for those balls to snap into place and hold the drill bit. In German markets, SDS stands for "Steck, Dreh, Sitz" (Insert, Twist, Stay). Cool, huh? And those are the major benefits of SDS systems. Spline drive bits and chucks are an older system that, like the SDS Max system, is designed with the above features in mind, but for the most heavy-duty masonry drilling; although, SDS Max systems include some advantages over Spline systems.     When Bosch introduced the first SDS system, it was simply called SDS. Later, improvements were made that helped the shank design hold more firmly, and the design changes were dubbed "SDS-Plus." However, the improvements did not have any impact on compatibility, so SDS and SDS-Plus are interchangeable in both terminology and function. For new tools, SDS-Plus (sometimes written "SDS+") has simply replaced SDS. SDS-Plus bit shanks have four indentions on them: two that are open-ended, and two that are close-ended (which keep the bit from flying out of the chuck). The SDS-Plus icon above shows a top view of an SDS-Plus shank, and depicts the orientation of its four grooves. Also, see the picture below for side views of SDS-Plus shanks:   SDS-Plus systems are the most common, since they're adapted for relatively less-heavy drilling (in comparison to larger hammer drills), and their shanks have a diameter of 10mm. [Back to top]     SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

HRC meaning inhardness

2. The number and type of grooves/keyways on the bit shank that fit into the innards of the chuck.   So, for example, any of the SDS-Plus bits pictured below (despite their differing bit diameter, length, and other features) will fit perfectly into any SDS/SDS-Plus chuck system, because their shank diameters are the same, and the number/placement of their grooves are the same. Comparably, any SDS MAX or Spline bit will also fit perfectly into any tool with a matching chuck system. (SDS and SDS-Plus are the only cross-compatible bit systems, making the terms interchangeable.) Here's the catch: Hammer drill and rotary hammer owners must know which chuck system their tool uses. The type of chuck system cannot be determined by simply looking at the chuck, probing its opening with a finger, or by any other means. Tools that use these systems will almost always be advertised with the name of the chuck system as part of the tool's advertised name. However, because a tool model number always corresponds to only one kind of chuck system, model numbers are used to pinpoint the exact tool (chuck system included) after sale. Also, the name of the chuck system may be written on the tool somewhere and can always be found in the user manual. The point is that if the chuck system isn't already known, then the tool's model number must be known in most cases to find out which system it uses. Example: The Bosch 11224VSR Hammer Drill uses an SDS-Plus system, and probably included that information in its advertised name. But, like its title on our parts page for this tool, chuck system details are usually omitted from a tool's title after sale, since the model number is included in the title and is the surest way of leading to accurate information concerning the tool.   If you have the model number of your tool but aren't sure about which chuck design it uses, try the following: Look up what the chuck system is in the user manual (often available online at manufacturer websites), or look for it written on the tool somewhere. If a manual isn't available, use the model number of the tool in a broad internet search to find out the tool's specifics. Look closely at an old bit. The chuck system to which it corresponds is almost always engraved somewhere on the hardware. If the above resources are not available or don't produce the needed information, simply try fitting the different types of bits into the chuck (SDS/SDS-plus, SDS Max, and Spline). The tool might need to be taken somewhere where hammer bits are sold for this test, if the variety of needed bits is not available otherwise. The correct bit is the only one that will fit into the chuck. After matching the right bit design to its mirror chuck system, other factors that determine bit type can be explored from there (bits for chiseling, cutting, digging, chipping, etc.) to match user preference and application. Below is a detailed description for each of the three chuck systems. [Back to top]   SDS/SDS-Plus, SDS Max, and Spline Chuck Systems Explained "Since they can be tough to keep separate, why the different chuck systems?" That's a fair question. Bosch developed the first SDS system back in 1975. In English-speaking markets, SDS stands for "Special Direct System." SDS chuck systems are specially adapted for concrete and other masonry hammering. In hammers that use traditional chucks, the striking piston uses part of its energy to move the heavy chuck piece back and forth, as well as the drill bit. In an SDS system, the flat end of the drill bit is the only thing that the piston hits and has to move. This makes its energy usage more direct, efficient, and effective. Also, the grooves in an SDS bit shank allow the bit to slide back and forth when it is hit by the piston, providing even more potential for the bit to be accelerated efficiently by the energy of the piston. The snappiest feature of the SDS systems is probably their one-hand bit changing. Inside each SDS chuck there are spring-loaded balls designed to fit into the grooves of SDS bit shanks. After being inserted into the chuck, an SDS bit just needs a little twist for those balls to snap into place and hold the drill bit. In German markets, SDS stands for "Steck, Dreh, Sitz" (Insert, Twist, Stay). Cool, huh? And those are the major benefits of SDS systems. Spline drive bits and chucks are an older system that, like the SDS Max system, is designed with the above features in mind, but for the most heavy-duty masonry drilling; although, SDS Max systems include some advantages over Spline systems.     When Bosch introduced the first SDS system, it was simply called SDS. Later, improvements were made that helped the shank design hold more firmly, and the design changes were dubbed "SDS-Plus." However, the improvements did not have any impact on compatibility, so SDS and SDS-Plus are interchangeable in both terminology and function. For new tools, SDS-Plus (sometimes written "SDS+") has simply replaced SDS. SDS-Plus bit shanks have four indentions on them: two that are open-ended, and two that are close-ended (which keep the bit from flying out of the chuck). The SDS-Plus icon above shows a top view of an SDS-Plus shank, and depicts the orientation of its four grooves. Also, see the picture below for side views of SDS-Plus shanks:   SDS-Plus systems are the most common, since they're adapted for relatively less-heavy drilling (in comparison to larger hammer drills), and their shanks have a diameter of 10mm. [Back to top]     SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

Steel hardnessHRC

Indentation hardness measures the resistance of a sample to material deformation due to a constant compression load from a sharp object. Tests for indentation hardness are primarily used in engineering and metallurgy. The tests work on the basic premise of measuring the critical dimensions of an indentation left by a specifically dimensioned and loaded indenter. Common indentation hardness scales are Rockwell, Vickers, Shore, and Brinell, amongst others.

SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

Dislocations provide a mechanism for planes of atoms to slip and thus a method for plastic or permanent deformation.[7] Planes of atoms can flip from one side of the dislocation to the other effectively allowing the dislocation to traverse through the material and the material to deform permanently. The movement allowed by these dislocations causes a decrease in the material's hardness.

HRC full form inhardness

Strength is a measure of the extent of a material's elastic range, or elastic and plastic ranges together. This is quantified as compressive strength, shear strength, tensile strength depending on the direction of the forces involved. Ultimate strength is an engineering measure of the maximum load a part of a specific material and geometry can withstand.

The toughness of a material is the maximum amount of energy it can absorb before fracturing, which is different from the amount of force that can be applied. Toughness tends to be small for brittle materials, because elastic and plastic deformations allow materials to absorb large amounts of energy.

However, while a hardness number thus depends on the stress-strain relationship, inferring the latter from the former is far from simple and is not attempted in any rigorous way during conventional hardness testing. (In fact, the Indentation Plastometry technique, which involves iterative FEM modelling of an indentation test, does allow a stress-strain curve to be obtained via indentation, but this is outside the scope of conventional hardness testing.) A hardness number is just a semi-quantitative indicator of the resistance to plastic deformation. Although hardness is defined in a similar way for most types of test – usually as the load divided by the contact area – the numbers obtained for a particular material are different for different types of test, and even for the same test with different applied loads. Attempts are sometimes made[11][12][13][14][15] to identify simple analytical expressions that allow features of the stress-strain curve, particularly the yield stress and Ultimate Tensile Stress (UTS), to be obtained from a particular type of hardness number. However, these are all based on empirical correlations, often specific to particular types of alloy: even with such a limitation, the values obtained are often quite unreliable. The underlying problem is that metals with a range of combinations of yield stress and work hardening characteristics can exhibit the same hardness number. The use of hardness numbers for any quantitative purpose should, at best, be approached with considerable caution.

"What type of drill bit fits my hammer drill?" This is one of the most common questions we get from hammer drill and rotary hammer owners here at eReplacementParts.com. The confusion is very understandable, considering that there are several drill bit systems and terms out there that sometimes overlap in definition and compatibility. We're happy to take this opportunity to sort through the jumble, break the information down, and make the task of finding the right bit easy, like it should be. The most important factor in matching a bit to its hammer drill is knowing the chuck system of the tool, and choosing bits designed to correspond to that system. For hammer drills and rotary hammers, there are three major chuck/bit design systems available: 1. SDS/SDS-Plus (in terms of compatibility, "SDS" and "SDS-Plus" are completely interchangeable.) 2. SDS Max, and 3. Spline Drive This article explains the design differences between these systems, and it explains why knowing a power hammer's chuck system design is the key to getting a compatible bit for that hammer.   Match the Bit Type to the Chuck System To find a compatible bit for your hammer drill or rotary hammer, you only need to know one thing: the chuck system (SDS/SDS-Plus, SDS Max, or Spline). It's that simple. Although there are other bit type considerations when making a purchase, as far as making sure that the bit shank will fit the hammer chuck, matching it to the chuck system is the one and only step. This is because the type of chuck system completely determines two things: 1. The diameter of the bit shank (the end of the drill bit that fits into the chuck), and 2. The number and type of grooves/keyways on the bit shank that fit into the innards of the chuck.   So, for example, any of the SDS-Plus bits pictured below (despite their differing bit diameter, length, and other features) will fit perfectly into any SDS/SDS-Plus chuck system, because their shank diameters are the same, and the number/placement of their grooves are the same. Comparably, any SDS MAX or Spline bit will also fit perfectly into any tool with a matching chuck system. (SDS and SDS-Plus are the only cross-compatible bit systems, making the terms interchangeable.) Here's the catch: Hammer drill and rotary hammer owners must know which chuck system their tool uses. The type of chuck system cannot be determined by simply looking at the chuck, probing its opening with a finger, or by any other means. Tools that use these systems will almost always be advertised with the name of the chuck system as part of the tool's advertised name. However, because a tool model number always corresponds to only one kind of chuck system, model numbers are used to pinpoint the exact tool (chuck system included) after sale. Also, the name of the chuck system may be written on the tool somewhere and can always be found in the user manual. The point is that if the chuck system isn't already known, then the tool's model number must be known in most cases to find out which system it uses. Example: The Bosch 11224VSR Hammer Drill uses an SDS-Plus system, and probably included that information in its advertised name. But, like its title on our parts page for this tool, chuck system details are usually omitted from a tool's title after sale, since the model number is included in the title and is the surest way of leading to accurate information concerning the tool.   If you have the model number of your tool but aren't sure about which chuck design it uses, try the following: Look up what the chuck system is in the user manual (often available online at manufacturer websites), or look for it written on the tool somewhere. If a manual isn't available, use the model number of the tool in a broad internet search to find out the tool's specifics. Look closely at an old bit. The chuck system to which it corresponds is almost always engraved somewhere on the hardware. If the above resources are not available or don't produce the needed information, simply try fitting the different types of bits into the chuck (SDS/SDS-plus, SDS Max, and Spline). The tool might need to be taken somewhere where hammer bits are sold for this test, if the variety of needed bits is not available otherwise. The correct bit is the only one that will fit into the chuck. After matching the right bit design to its mirror chuck system, other factors that determine bit type can be explored from there (bits for chiseling, cutting, digging, chipping, etc.) to match user preference and application. Below is a detailed description for each of the three chuck systems. [Back to top]   SDS/SDS-Plus, SDS Max, and Spline Chuck Systems Explained "Since they can be tough to keep separate, why the different chuck systems?" That's a fair question. Bosch developed the first SDS system back in 1975. In English-speaking markets, SDS stands for "Special Direct System." SDS chuck systems are specially adapted for concrete and other masonry hammering. In hammers that use traditional chucks, the striking piston uses part of its energy to move the heavy chuck piece back and forth, as well as the drill bit. In an SDS system, the flat end of the drill bit is the only thing that the piston hits and has to move. This makes its energy usage more direct, efficient, and effective. Also, the grooves in an SDS bit shank allow the bit to slide back and forth when it is hit by the piston, providing even more potential for the bit to be accelerated efficiently by the energy of the piston. The snappiest feature of the SDS systems is probably their one-hand bit changing. Inside each SDS chuck there are spring-loaded balls designed to fit into the grooves of SDS bit shanks. After being inserted into the chuck, an SDS bit just needs a little twist for those balls to snap into place and hold the drill bit. In German markets, SDS stands for "Steck, Dreh, Sitz" (Insert, Twist, Stay). Cool, huh? And those are the major benefits of SDS systems. Spline drive bits and chucks are an older system that, like the SDS Max system, is designed with the above features in mind, but for the most heavy-duty masonry drilling; although, SDS Max systems include some advantages over Spline systems.     When Bosch introduced the first SDS system, it was simply called SDS. Later, improvements were made that helped the shank design hold more firmly, and the design changes were dubbed "SDS-Plus." However, the improvements did not have any impact on compatibility, so SDS and SDS-Plus are interchangeable in both terminology and function. For new tools, SDS-Plus (sometimes written "SDS+") has simply replaced SDS. SDS-Plus bit shanks have four indentions on them: two that are open-ended, and two that are close-ended (which keep the bit from flying out of the chuck). The SDS-Plus icon above shows a top view of an SDS-Plus shank, and depicts the orientation of its four grooves. Also, see the picture below for side views of SDS-Plus shanks:   SDS-Plus systems are the most common, since they're adapted for relatively less-heavy drilling (in comparison to larger hammer drills), and their shanks have a diameter of 10mm. [Back to top]     SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

1. The diameter of the bit shank (the end of the drill bit that fits into the chuck), and 2. The number and type of grooves/keyways on the bit shank that fit into the innards of the chuck.   So, for example, any of the SDS-Plus bits pictured below (despite their differing bit diameter, length, and other features) will fit perfectly into any SDS/SDS-Plus chuck system, because their shank diameters are the same, and the number/placement of their grooves are the same. Comparably, any SDS MAX or Spline bit will also fit perfectly into any tool with a matching chuck system. (SDS and SDS-Plus are the only cross-compatible bit systems, making the terms interchangeable.) Here's the catch: Hammer drill and rotary hammer owners must know which chuck system their tool uses. The type of chuck system cannot be determined by simply looking at the chuck, probing its opening with a finger, or by any other means. Tools that use these systems will almost always be advertised with the name of the chuck system as part of the tool's advertised name. However, because a tool model number always corresponds to only one kind of chuck system, model numbers are used to pinpoint the exact tool (chuck system included) after sale. Also, the name of the chuck system may be written on the tool somewhere and can always be found in the user manual. The point is that if the chuck system isn't already known, then the tool's model number must be known in most cases to find out which system it uses. Example: The Bosch 11224VSR Hammer Drill uses an SDS-Plus system, and probably included that information in its advertised name. But, like its title on our parts page for this tool, chuck system details are usually omitted from a tool's title after sale, since the model number is included in the title and is the surest way of leading to accurate information concerning the tool.   If you have the model number of your tool but aren't sure about which chuck design it uses, try the following: Look up what the chuck system is in the user manual (often available online at manufacturer websites), or look for it written on the tool somewhere. If a manual isn't available, use the model number of the tool in a broad internet search to find out the tool's specifics. Look closely at an old bit. The chuck system to which it corresponds is almost always engraved somewhere on the hardware. If the above resources are not available or don't produce the needed information, simply try fitting the different types of bits into the chuck (SDS/SDS-plus, SDS Max, and Spline). The tool might need to be taken somewhere where hammer bits are sold for this test, if the variety of needed bits is not available otherwise. The correct bit is the only one that will fit into the chuck. After matching the right bit design to its mirror chuck system, other factors that determine bit type can be explored from there (bits for chiseling, cutting, digging, chipping, etc.) to match user preference and application. Below is a detailed description for each of the three chuck systems. [Back to top]   SDS/SDS-Plus, SDS Max, and Spline Chuck Systems Explained "Since they can be tough to keep separate, why the different chuck systems?" That's a fair question. Bosch developed the first SDS system back in 1975. In English-speaking markets, SDS stands for "Special Direct System." SDS chuck systems are specially adapted for concrete and other masonry hammering. In hammers that use traditional chucks, the striking piston uses part of its energy to move the heavy chuck piece back and forth, as well as the drill bit. In an SDS system, the flat end of the drill bit is the only thing that the piston hits and has to move. This makes its energy usage more direct, efficient, and effective. Also, the grooves in an SDS bit shank allow the bit to slide back and forth when it is hit by the piston, providing even more potential for the bit to be accelerated efficiently by the energy of the piston. The snappiest feature of the SDS systems is probably their one-hand bit changing. Inside each SDS chuck there are spring-loaded balls designed to fit into the grooves of SDS bit shanks. After being inserted into the chuck, an SDS bit just needs a little twist for those balls to snap into place and hold the drill bit. In German markets, SDS stands for "Steck, Dreh, Sitz" (Insert, Twist, Stay). Cool, huh? And those are the major benefits of SDS systems. Spline drive bits and chucks are an older system that, like the SDS Max system, is designed with the above features in mind, but for the most heavy-duty masonry drilling; although, SDS Max systems include some advantages over Spline systems.     When Bosch introduced the first SDS system, it was simply called SDS. Later, improvements were made that helped the shank design hold more firmly, and the design changes were dubbed "SDS-Plus." However, the improvements did not have any impact on compatibility, so SDS and SDS-Plus are interchangeable in both terminology and function. For new tools, SDS-Plus (sometimes written "SDS+") has simply replaced SDS. SDS-Plus bit shanks have four indentions on them: two that are open-ended, and two that are close-ended (which keep the bit from flying out of the chuck). The SDS-Plus icon above shows a top view of an SDS-Plus shank, and depicts the orientation of its four grooves. Also, see the picture below for side views of SDS-Plus shanks:   SDS-Plus systems are the most common, since they're adapted for relatively less-heavy drilling (in comparison to larger hammer drills), and their shanks have a diameter of 10mm. [Back to top]     SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

1. SDS/SDS-Plus (in terms of compatibility, "SDS" and "SDS-Plus" are completely interchangeable.) 2. SDS Max, and 3. Spline Drive This article explains the design differences between these systems, and it explains why knowing a power hammer's chuck system design is the key to getting a compatible bit for that hammer.   Match the Bit Type to the Chuck System To find a compatible bit for your hammer drill or rotary hammer, you only need to know one thing: the chuck system (SDS/SDS-Plus, SDS Max, or Spline). It's that simple. Although there are other bit type considerations when making a purchase, as far as making sure that the bit shank will fit the hammer chuck, matching it to the chuck system is the one and only step. This is because the type of chuck system completely determines two things: 1. The diameter of the bit shank (the end of the drill bit that fits into the chuck), and 2. The number and type of grooves/keyways on the bit shank that fit into the innards of the chuck.   So, for example, any of the SDS-Plus bits pictured below (despite their differing bit diameter, length, and other features) will fit perfectly into any SDS/SDS-Plus chuck system, because their shank diameters are the same, and the number/placement of their grooves are the same. Comparably, any SDS MAX or Spline bit will also fit perfectly into any tool with a matching chuck system. (SDS and SDS-Plus are the only cross-compatible bit systems, making the terms interchangeable.) Here's the catch: Hammer drill and rotary hammer owners must know which chuck system their tool uses. The type of chuck system cannot be determined by simply looking at the chuck, probing its opening with a finger, or by any other means. Tools that use these systems will almost always be advertised with the name of the chuck system as part of the tool's advertised name. However, because a tool model number always corresponds to only one kind of chuck system, model numbers are used to pinpoint the exact tool (chuck system included) after sale. Also, the name of the chuck system may be written on the tool somewhere and can always be found in the user manual. The point is that if the chuck system isn't already known, then the tool's model number must be known in most cases to find out which system it uses. Example: The Bosch 11224VSR Hammer Drill uses an SDS-Plus system, and probably included that information in its advertised name. But, like its title on our parts page for this tool, chuck system details are usually omitted from a tool's title after sale, since the model number is included in the title and is the surest way of leading to accurate information concerning the tool.   If you have the model number of your tool but aren't sure about which chuck design it uses, try the following: Look up what the chuck system is in the user manual (often available online at manufacturer websites), or look for it written on the tool somewhere. If a manual isn't available, use the model number of the tool in a broad internet search to find out the tool's specifics. Look closely at an old bit. The chuck system to which it corresponds is almost always engraved somewhere on the hardware. If the above resources are not available or don't produce the needed information, simply try fitting the different types of bits into the chuck (SDS/SDS-plus, SDS Max, and Spline). The tool might need to be taken somewhere where hammer bits are sold for this test, if the variety of needed bits is not available otherwise. The correct bit is the only one that will fit into the chuck. After matching the right bit design to its mirror chuck system, other factors that determine bit type can be explored from there (bits for chiseling, cutting, digging, chipping, etc.) to match user preference and application. Below is a detailed description for each of the three chuck systems. [Back to top]   SDS/SDS-Plus, SDS Max, and Spline Chuck Systems Explained "Since they can be tough to keep separate, why the different chuck systems?" That's a fair question. Bosch developed the first SDS system back in 1975. In English-speaking markets, SDS stands for "Special Direct System." SDS chuck systems are specially adapted for concrete and other masonry hammering. In hammers that use traditional chucks, the striking piston uses part of its energy to move the heavy chuck piece back and forth, as well as the drill bit. In an SDS system, the flat end of the drill bit is the only thing that the piston hits and has to move. This makes its energy usage more direct, efficient, and effective. Also, the grooves in an SDS bit shank allow the bit to slide back and forth when it is hit by the piston, providing even more potential for the bit to be accelerated efficiently by the energy of the piston. The snappiest feature of the SDS systems is probably their one-hand bit changing. Inside each SDS chuck there are spring-loaded balls designed to fit into the grooves of SDS bit shanks. After being inserted into the chuck, an SDS bit just needs a little twist for those balls to snap into place and hold the drill bit. In German markets, SDS stands for "Steck, Dreh, Sitz" (Insert, Twist, Stay). Cool, huh? And those are the major benefits of SDS systems. Spline drive bits and chucks are an older system that, like the SDS Max system, is designed with the above features in mind, but for the most heavy-duty masonry drilling; although, SDS Max systems include some advantages over Spline systems.     When Bosch introduced the first SDS system, it was simply called SDS. Later, improvements were made that helped the shank design hold more firmly, and the design changes were dubbed "SDS-Plus." However, the improvements did not have any impact on compatibility, so SDS and SDS-Plus are interchangeable in both terminology and function. For new tools, SDS-Plus (sometimes written "SDS+") has simply replaced SDS. SDS-Plus bit shanks have four indentions on them: two that are open-ended, and two that are close-ended (which keep the bit from flying out of the chuck). The SDS-Plus icon above shows a top view of an SDS-Plus shank, and depicts the orientation of its four grooves. Also, see the picture below for side views of SDS-Plus shanks:   SDS-Plus systems are the most common, since they're adapted for relatively less-heavy drilling (in comparison to larger hammer drills), and their shanks have a diameter of 10mm. [Back to top]     SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.

"Like magic. I took a picture of the model number on my refrigerator, and the app identified it right away ... Very convenient. I'm impressed." ★★★★★ -Clever Jeff ★★★★★

The way to inhibit the movement of planes of atoms, and thus make them harder, involves the interaction of dislocations with each other and interstitial atoms. When a dislocation intersects with a second dislocation, it can no longer traverse through the crystal lattice. The intersection of dislocations creates an anchor point and does not allow the planes of atoms to continue to slip over one another[10] A dislocation can also be anchored by the interaction with interstitial atoms. If a dislocation comes in contact with two or more interstitial atoms, the slip of the planes will again be disrupted. The interstitial atoms create anchor points, or pinning points, in the same manner as intersecting dislocations.

Hardness of a material to deformation is dependent on its microdurability or small-scale shear modulus in any direction, not to any rigidity or stiffness properties such as its bulk modulus or Young's modulus. Stiffness is often confused for hardness.[5][6] Some materials are stiffer than diamond (e.g. osmium) but are not harder, and are prone to spalling and flaking in squamose or acicular habits.

Here's the catch: Hammer drill and rotary hammer owners must know which chuck system their tool uses. The type of chuck system cannot be determined by simply looking at the chuck, probing its opening with a finger, or by any other means. Tools that use these systems will almost always be advertised with the name of the chuck system as part of the tool's advertised name. However, because a tool model number always corresponds to only one kind of chuck system, model numbers are used to pinpoint the exact tool (chuck system included) after sale. Also, the name of the chuck system may be written on the tool somewhere and can always be found in the user manual. The point is that if the chuck system isn't already known, then the tool's model number must be known in most cases to find out which system it uses. Example: The Bosch 11224VSR Hammer Drill uses an SDS-Plus system, and probably included that information in its advertised name. But, like its title on our parts page for this tool, chuck system details are usually omitted from a tool's title after sale, since the model number is included in the title and is the surest way of leading to accurate information concerning the tool.   If you have the model number of your tool but aren't sure about which chuck design it uses, try the following: Look up what the chuck system is in the user manual (often available online at manufacturer websites), or look for it written on the tool somewhere. If a manual isn't available, use the model number of the tool in a broad internet search to find out the tool's specifics. Look closely at an old bit. The chuck system to which it corresponds is almost always engraved somewhere on the hardware. If the above resources are not available or don't produce the needed information, simply try fitting the different types of bits into the chuck (SDS/SDS-plus, SDS Max, and Spline). The tool might need to be taken somewhere where hammer bits are sold for this test, if the variety of needed bits is not available otherwise. The correct bit is the only one that will fit into the chuck. After matching the right bit design to its mirror chuck system, other factors that determine bit type can be explored from there (bits for chiseling, cutting, digging, chipping, etc.) to match user preference and application. Below is a detailed description for each of the three chuck systems. [Back to top]   SDS/SDS-Plus, SDS Max, and Spline Chuck Systems Explained "Since they can be tough to keep separate, why the different chuck systems?" That's a fair question. Bosch developed the first SDS system back in 1975. In English-speaking markets, SDS stands for "Special Direct System." SDS chuck systems are specially adapted for concrete and other masonry hammering. In hammers that use traditional chucks, the striking piston uses part of its energy to move the heavy chuck piece back and forth, as well as the drill bit. In an SDS system, the flat end of the drill bit is the only thing that the piston hits and has to move. This makes its energy usage more direct, efficient, and effective. Also, the grooves in an SDS bit shank allow the bit to slide back and forth when it is hit by the piston, providing even more potential for the bit to be accelerated efficiently by the energy of the piston. The snappiest feature of the SDS systems is probably their one-hand bit changing. Inside each SDS chuck there are spring-loaded balls designed to fit into the grooves of SDS bit shanks. After being inserted into the chuck, an SDS bit just needs a little twist for those balls to snap into place and hold the drill bit. In German markets, SDS stands for "Steck, Dreh, Sitz" (Insert, Twist, Stay). Cool, huh? And those are the major benefits of SDS systems. Spline drive bits and chucks are an older system that, like the SDS Max system, is designed with the above features in mind, but for the most heavy-duty masonry drilling; although, SDS Max systems include some advantages over Spline systems.     When Bosch introduced the first SDS system, it was simply called SDS. Later, improvements were made that helped the shank design hold more firmly, and the design changes were dubbed "SDS-Plus." However, the improvements did not have any impact on compatibility, so SDS and SDS-Plus are interchangeable in both terminology and function. For new tools, SDS-Plus (sometimes written "SDS+") has simply replaced SDS. SDS-Plus bit shanks have four indentions on them: two that are open-ended, and two that are close-ended (which keep the bit from flying out of the chuck). The SDS-Plus icon above shows a top view of an SDS-Plus shank, and depicts the orientation of its four grooves. Also, see the picture below for side views of SDS-Plus shanks:   SDS-Plus systems are the most common, since they're adapted for relatively less-heavy drilling (in comparison to larger hammer drills), and their shanks have a diameter of 10mm. [Back to top]     SDS Max bits are only compatible in SDS Max chuck systems. SDS Max is designed for even heavier-duty work than SDS-Plus, and accordingly, the range of SDS Max bit sizes leans more toward the larger end of masonry drill bits. In many ways, the SDS Max system was designed to improve upon and replace the older Spline drive system. The main improvement of this system is that it allows for more piston travel, so that when the piston hits the bit, it hits harder and the bit cuts more efficiently. Despite the design upgrades, Spline drive systems remain popular with some users and are still manufactured. SDS Max bit shanks have five indentions on them: three that are open-ended, and two that are close-ended (keeping the bit from flying out of the chuck). The SDS Max icon above shows a top view of an SDS Max shank, and displays the situation of its five grooves. Here's a picture with side views of SDS Max bit shanks: SDS Max systems are the newest, and, overall, best systems for the most heavy masonry drilling out there. Their shanks have a diameter of 18mm. [Back to top]     Spline drive bits are only compatible in spline drive chuck systems. As discussed above, Spline drive systems are for the most burdensome drilling workloads, like SDS Max, but they are an older system. Although the SDS Max system improves upon the Spline drive design, many users still prefer Spline drive and continue to use it out of preference. The icon above shows a top view of a Spline drive shank, and shows its many-grooved design. A Spline bit shank from the side: Spline drive shanks have a diameter of 19mm. [Back to top]   Chuck Adapters for Hammering Drills Yes, adapters are available that allow bits from different systems to be used in the same tool. Most opinions on these adapters suggest that it's best to avoid them if possible, since one more part (and a loose one at that) can just mean an opportunity for the part to break or be lost. But chuck adapters are also very handy when they're the only available option. Chuck adapters are available to convert between the following systems: SDS Max        ---->      Spline Drive Spline Drive    ---->      SDS Max SDS Max        ---->      SDS/SDS-Plus Spline Drive    ---->      SDS/SDS-Plus The obvious restriction is that chuck adapters don't (and shouldn't) convert from the smaller SDS/SDS-Plus systems to the larger SDS Max and Spline drive systems. If chuck adapters were available for an upgraded conversion, the hammer drills with the original SDS-Plus system probably wouldn't be rated high enough to handle the workload for which SDS Max and Spline bits would be required. [Back to top]   2-Flute and 4-Flute Bits So far, this article has only discussed differences between hammer drill bits that relate to their compatibility in chucks. Of course, after compatibility is resolved, shoppers still have a host of drill bit types to choose from to match bits to a given application. One of the most important and common decisions that bit shoppers have to make when looking for masonry bits is the choice between 2- and 4-flute bits. Flutes are the cross section pieces on the tips of masonry bits that give them their shape, as can be seen in the picture above. 2-flute bits are a more traditional design of masonry bits. The more recently-developed, 4-flute bits cut much more efficiently. In general, the 4-flute bits cut faster, with more energy efficiency, less bit wear, and get stuck in their holes less easily than 2-flute masonry bits. This is especially true when the bit makes contact with rebar or other metals in concrete. 2-flute bits easily get caught up on obstructions like rebar, and sometimes get really stuck because of it. The 4-flute design helps the bit just continue to cut right through the material. [Back to top] Conclusion Those are the major pointers when it comes to finding and selecting a compatible masonry bit for a given power hammer. The chuck system of the tool must be known, and knowing the tool's model number is the surest way to find out which chuck system the tool uses. Visit our Hammer Drill Bits page to begin your search for the masonry bit your power hammer needs. Or, browse our Hammer Drills and Rotary Hammer pages to find your hammer's tool parts page.   [Back to top] What we're about.