Centaur also offers RDT/ER tapping collets. These collets will inexpensively convert a standard collet chuck into a length compensating, Quick-change tapping chuck with square drive.

Collets are best for gripping smaller workpieces (ranging from 1/16″ to 2.5″) compared to chucks, which are better suited for gripping larger parts or parts with inconsistent diameters.

Hold nut in vertical position and remove nut at an angle. Collet is automatically withdrawn from chuck by excentric ring of nut when unscrewed.

Kreg pocket hole jigs come with a special stepped drill bit and a stop collar. The stop collar helps stop the drill bit at the appropriate distance without making the pocket hole too deep.

The ER chuck, ER collet and ER nut must be thoroughly cleaned before assembling to maintain accuracy. Use a benchtop ultrasonic cleaner to dislodge fine chips and debris. You can also use a bottle-type brush to clean the inner diameter of the collet and a toothbrush-style brush to clean the exterior.

The number following ER refers to the collet’s range. An ER 11 is a collet that has a range of 0.5-7mm or 1/16″ -1/4″. An ER 20 is a collet that has a range of 0.5-13mm or 1/16″-1/2″.

Cutting tools should be inserted into the collet the full length of the bore wherever possible. Failure to insert the cutting tool into at least 2/3 of the bore may distort the collet. Collets should be cleaned and oiled prior to storage.

Compared to standard 3-jaw chucks, collet chucks are more affordable, perform better at higher RPMs, have faster changeover, better concentricity, greater accuracy. and are best suited for gripping small parts.

RDG/TG Collets are used for Milling, Drilling and Rigid Tapping. RDG/TG collets are available sealed for coolant through applications. RDG/TG collets. RDG/TG in 1/64” Increments or .5mm increments for metric sized tools.

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AF collets are available in 1/64” increments and limited metrics sizes. RDF collets are designed to collapse 1/64. Size ranges are as follows:

Collet size usually indicates the size tool the collet will hold. (e.g. ER16 will hold a tool that is 16mm in diameter). Refer to the collet sizes chart below for some common measurements:

Even though you may pick up a board with a given dimension, not all boards are made equal, and there can be variation from board to board (and even across the same board). It is always a good idea to break out that tape measure and check the thickness.

When building with pocket holes, you always want to use pocket hole screws. These are different from regular wood screws.

Drill the pocket holes through the guide holes in the jig. The depth collar automatically stops the drill at the right height.

Important – Make sure that the depth collar is tight. If it moves as you push down the drill, the pocket holes will be deeper than needed, and you will not get a strong joint. A quick visual check at the end of drilling holes on a board to see if the hole is sticking out of the board is a great way to make sure you don’t over-drill.

1. Spindle performance. Compared to the large jaw chuck, the collet chuck’s smaller size allows for faster acceleration, making it the best choice for turning at high spindle RPMs.

Centaur manufactures each collet from high-grade spring steel and are hardened and fully ground for absolute precision. Each Centaur collet is 100% inspected for the highest possible accuracy.

The guide marks at the top of the jig tell you the locations where the pocket holes will be drilled. You want to make at least two pocket holes in a board in order because one pocket hole becomes a pivot point.

A simple step by step guide to show you how to use a pocket hole jig by Kreg Tools. Plus everything you need to know to make strong pocket hole joints like a pro!

RDG/TG Collets are within .0005 T.I.R. The collet chucks are within .0002 T.I.R. from the cone to the collet seat bore. The nuts are designed to float to allow for centering of the collet. RDG/TG systems when properly cleaned and assembled can achieve approximately .001 T.I.R. on a cutting tool shank in the assembly at a checking point length of about 2-3 times the diameter of the cutting tool. The collapse range of the RDG/TG Collets are 1/64”. As with all Collets it is recommended that the collet be used at the nominal or largest diameter. Sealed Collets do not have a collapse range and must be used at the exact size.

4. Small parts. Collet chuck are best for machining smaller parts, due to their better grip, weight, acceleration and changeover speed. Standard 3-jaw chucks are great for larger parts, objects with inconsistent diameter, larger axial dimensions, or when working with a large variety of work pieces.

The RDG/TG Collets must be snapped into the Clamping Nut prior to installing onto the Collet Chuck. Collets can be removed from the clamping nut by holding the small end of the collet and tilting the collet angularly until it is removed from the nut. Do not attempt to remove the collet from the clamping nut by forcing the collet out from the front of the collet nut using a punch or screwdriver as this will damage the collet and clamping nut. For maximum accuracy and holding strength RDG/TG Collets must be tightened correctly, maximum tightening torque is as follows:

RD/ER Collets must be tightened correctly. Many machinists have been trained that nothing is ever too tight. This is particularly not true with collets and collet chucks. Overtightening a collet chuck will distort the collet and actually diminish the holding strength and accuracy. Maximum tightening torque for RD/ER Systems is as follows:

The Centaur Green Zone refers to full-radius contact design that centralizes the cutting tool. This provides concentricity that increases tool life, enhances feed rates and rpm, and improves workpiece accuracy and finish.

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Collet closers remove unnecessary repetitive steps from the process of working with lathes, grinders, and CNC rotary tables.

I highly recommend having at least one face clamp and one right-angle clamp handy. You can also use other larger F-style clamps for bigger projects.

Total Indicator Reading (TIR), is the difference between minimum and maximum readouts found when an indicator is run along the surface of a part while it is rotated along an axis. The TIR measures any discrepancy found in the planar, cylindrical, or contoured surface of a part. TIR is important for testing whether the flatness, circular, concentric, or any other shape for a part is maintained precisely or whether adjustments need to be made before the part can be used in a bigger machine.

Centaur external flow ER collets are also extremely beneficial for through holes with oil hole cutting tools, as this will ensure that the cutting is properly cooled completely throughout the entire cycle. In many applications as the cutting tool is passing through or breaking through the workpiece the coolant may be just passing through the hole, with an external flow sealed collet one can be assured the complete cutting edge and lands of the drill are cooled throughout the complete cycle.

ER collet systems are truly interchangeable. All manufacturers of the ER collet system should conform to the DIN6499 standard. This becomes important to users that may have toolholding systems from different Toolholding System Manufacturers. As tools are taken out of the tool crib and reassembled for different jobs, if all the RD/ER system components are in good condition, and are from Quality Toolholding System Manufacturers, the collet and tool should achieve the DIN 6499 accuracy.

Use the thickness you measured and set the jig height accordingly. On the K4, K5, Kreg 320 and Kreg 520, you need to do this manually.

RDA/DA Collets are manufactured to within .0005 T.I.R. outer diameter to inner diameter. The length of parrallelism between the two female contacting angles in the chuck controls the accuracy of the system and is held to within plus or minus .0002. The clamping nut floats slightly to allow the chuck to center the collet. Normal accuracy is approximately .001 T.I.R at the face of the collet chuck.

I want to join 2x4s cut at a 45 degree angle to form a 90 degree corner for the frame of a table. How do I set my Kreg jig to do that operation?

Read 7 more important Pocket hole tips ,including what to do when joining different thickness boards and the special setting when using plywood.

Spring collet chucks don’t have backplate and arms, instead the chuck is a hollow cylinder, much like a sized attachment for a socket wrench.

Sealed ER Collets for coolant through applications do not have a collapse range, and must be used at exact size. The radius of the collet must exactly match the radius of the cutting tool shank in order to maintain a complete seal. If companies claim that they have sealed collets with a collapse range please keep in mind that if the radius does not match exactly coolant canals will be created by the mismatched radius of an improperly sized collet.

It took me a few iterations to figure out exactly what I needed to do to get the joints to work. And then, it took a few months before I understood exactly why my pocket hole joints weren’t always the strongest in spite of following all the “rules.”

When using endmills or any round shank cutting tool, collets and collet chucks centralize the cutting tool, unlike conventional sidelock endmill holders that push the tool to the side of the bore of the holder with a set screw. This method creates a small contact area on the cutting tool and shifts the cutting tool from the true centerline of the Machine spindle. With the cutting tool off-center, the cutting tool edges have an uneven load and will wear out prematurely. Collets and Collet Chucks centralizing the cutting tool will result in increased tool life, higher feed rates, better workpiece accuracy and enhanced workpiece finish. Carbide endmills are usually not supplied with a weldon or locking flat for side lock endmill holders. This is because they are not designed to be used in side lock endmill holders. Many Machinists hand grind a locking flat on to the shank of the carbide end mills to use them in side lock holders, perhaps it would be better to use them in the type of tool that they are designed to be used in.

Standard collet chucks consist of a round flat backplate with either four or six arms rising up around the plate’s circumference.

A Kreg Jig is a woodworking jig made by the Kreg Tool Company that helps make pocket holes. While there are many other pocket hole jig brands on the market, the Kreg Jig is the most popular one, and I love and use it.

Centaur offer RD/ER collets in full millimeter sizes, .5mm sizes and true inch size collets in 1/32″ increments from inventory.

Anika – great video and I love your workbench – my next project! I only wish my hardware store could cut 2 pieces the same size! Only once when a woman was working the saw were all the cuts I needed spot on. I have a small circular saw but am terrified to use it.

Want to know how to fill pocket holes so they can’t be seen in your finished project? See How to Fill Pocket Holes – 4 Simple Techniques

A chuck is a specialized type of clamp used to hold an object with radial symmetry, especially a cylinder. In drills and mills it holds the rotating tool whereas in lathes it holds the rotating workpiece. On a lathe the chuck is mounted on the spindle which rotates within the headstock. [source: everythingwhat]

The most common thicknesses you will be working with are ½”, ¾”, and 1½”. Learn more about the nominal and actual thickness of lumber here.

The only type of joint a pocket hole cannot make are end to end joints – you cannot make a board longer using pocket holes.

Pocket holes are very popular in woodworking projects for beginners and advanced woodworkers alike. Although “fine” woodworkers frown on them, they are really easy to use and great for building quick, strong projects.

You place the 45degree end flush to the bottom – creating a 45 degree angle with the bottom of the Kreg Jig. I hope this helps. I am going to be doing a build with angles next week and will try to get some pictures added to this post.

Never try to install a cutting tool with a larger shank than the maximum or nominal diameter of the collet to expand the collet. Most ER Collets are designed to collapse 1mm or .039. For example: If the cutting tool shank is 4.2mm a 4-3mm is not suitable. A 4.5-3.5mm collet would be required.

The high gripping strength RDO collet system was originated in Europe and are sometimes known as Ortlieb style collets or Full Grip Collets. Many machines designed for woodworking also use this system. This system is recommended for milling, drilling and boring applications. Many high production routing systems manufacturers have standardized on this system. Size Ranges are as follows:

Structurally, chucks are designed to be tightened around an object. In contrast, collets use clamping pressure by forming a collar around the tool being held.

When pocket hole screws are used to join this board to another board, the screws go in at an angle. This creates a stronger joint than if a screw were to go straight into the wood.

Mixing components of Toolholding Systems other than RD/ER can have varying results. While other Toolholding systems may be “interchangeable”, none of the Toolholding Systems Manufacturers know the tolerances and specifications others are using for all of the components.

RDG/TG collets achieve higher accuracy and greater gripping strength than DA collets and some other popular collet systems. This system will perform well in applications up to 10,000 RPM. RDG/TG collets are also known in the industry as DF, BG, VDF, and PG collets.

Once assembled, a normal machining environment will not affect the ER toolholding assembly. The ER collet must be installed into the nut (see assembly instructions) before engagement with the collet chuck to ensure the ER collet is seated into the 30 degree concave angle of the nut. Putting the ER collet into the chuck and then installing the nut will result in a condition that the eccentric ring of nut will engage only one side of the collet and produce poor results such as runout and drastically reduced holding strength.

Be sure to drive until the torque limit is reached. However, be sure to not overdrive the screw or it will strip the pocket hole.

Collets use clamping pressure by forming a collar around the tool being held, providing a stronger grip and better accuracy.

Are you wondering how to use a Kreg Jig to make pocket holes in mitered and angled cuts? See How to make pocket holes in mitered cuts!

Centaur Sealed ER collets are available with internal flow for oil hole tools or, with external flow (coolant canals through the collet) for use with cutting tools with or without oil holes. The external flow collets are especially beneficial for applications where there is coolant through the spindle but lower cost solid cutting tools are desired or applications where oil hole tools are used in through holes.

Below is the basic rule I use to drill pocket holes. Always do a visual check to make sure that the board is covering the holes on the jig because you don’t want holes along the side of your board.

Pocket holes are pre-drilled holes made at an angle – typically 15 degrees. These holes look like a pocket, hence the name pocket holes.

Just like all other lumber, the thickness of plywood is usually not exactly as noted. ¾” plywood is rarely exactly ¾” but it is usually 1/32” or 1/16” smaller. With a 1/32” difference, you can get away with a ¾” setting on the drill bit collar. But for larger variations, you can move the collar slightly above the ¾” setting and make the pocket holes.

If you would prefer to watch a video, I have a detailed video about pocket hole basics, how to make pocket holes, and how to join the boards.

It was the first tool I bought specifically for woodworking. I already owned a power drill, and I bought the Kreg Jig K4. Using that (and boards cut up at The Home Depot), I built my first projects—the kid’s table and chair set and my workbench.

Pocket holes are a beginner-friendly joinery method. Here is a simple step-by-step guide to understanding how to use a Kreg pocket hole jig and build projects using pocket hole joinery.

Thanks Debi. I am glad you enjoyed it. Yes, getting the hardware store to cut pieces precisely can be quite a challenge. I would recommend a miter saw instead of a circular saw. It is a lot easier to use and not too overwhelming. A miter saw is the first saw I started out with too.

What if you are working with one of the common board thicknesses that aren’t ½”, ¾”, or 1½”? If you are using a Kreg 720, you can easily adjust for the thickness using the markings on the back of the jig. For other jigs, you want to move the drill bit collar to account for the difference.

ER collets are recommended for Drilling, Milling, Rigid Tapping, Tapping (with Length Compensation), Reaming, Boring, Coolant Through, External Coolant Through, and High Precision Grinding.

The TG chuck, TG collet and TG nut must be thoroughly cleaned before assembling to maintain accuracy. A benchtop ultrasonic cleaner will dislodge fine chips and debris or, a bottle type brush can be used for cleaning the inner diameter of the collet and a toothbrush style can be used to clean the exterior. Once assembled a normal machining environment will not affect the toolholding assembly.

Position the board you want to drill the pocket hole in on the jig and clamp it, or clamp the jig on the board (for the Kreg 320).

Centaur’s ER rigid tapping collets with square drive are available in inch or metric sizes, standard or sealed for internal or external coolant flow.

I highly recommend using clamps while putting boards together. Clamps are like having an extra set (or two) of hands that hold the boards together really tightly.

The RD / ER collet system is the only popular Toolholding system in which all components (ER chucks, ER collets and ER clamping nuts) are standardized by DIN 6499. Most Toolholding Collet systems state the collet is .0005 or .001 T.I.R. but, that does not mean that this is the accuracy one will achieve on the cutting tool when mounted into the chuck. The accuracy of the RD/ER assembly is guaranteed to conform to the DIN 6499 Table.

ER Collets are also very economical when compared with other popular collet systems. Collets work best when used at nominal or full diameter but when the economy is desired this system compares very favorably with other systems. If a user would like to cover a range of 1/8-1″ with a toolholding system please consider that with the RD/ER System this only requires 23 collets. With a TG system of the same capacity it takes 59 collets to cover the same range. When compared with DA collets with a capacity of 1/16-3/4″ the RD/ER system only requires 18 collets while the DA needs 45 collets to cover the same range. This represents a significant cost saving while improving accuracy, and versatility.

This highly accurate Acura-Flex collet system (AF collet system) was originated by Universal Engineering. RDF/AF Collets are recommended for drilling, milling and boring applications. RDF/AF collets are also known in the industry as BF collets.

Collets 101: The Definitive Guide covers five popular collet series: ER collets, TG collets, DA collets, AF collets, and RDO collets. In each section, you will find: recommended uses for each type of collet, along with accuracy metrics (T.I.R.), and tips for how to care for each collet system. If you are new to all of this, please refer to the FAQ & Glossary at the end of this guide for some answers to common beginner questions.

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2. Tight tolerances. Collet chucks do not suffer the reduce clamping force caused by centrifugal force that affect jaw chucks.

A router collet is a collet used to clamp router bits in a router. The collet works with the collet nut and the router shaft (connected directly to the motor) .

Centaur manufactures each collet from high-grade spring steel and are hardened and fully ground for absolute precision. Centaur Certified Collets are 100% inspected for Function and Concentricity with specialized in-process and post-process gaging. They are certified to be within published specifications.

Centaur manufactures the widest variety of exact size collets in the industry to ensure you get the most out of your cutting tools, to reduce downtime and tooling costs.

RDA/DA Collets are recommended for drilling. RDA/DA Collets were originally designed to clamp well on slightly uneven surfaces such as jobbers or taper length type drills. RDA/DA Collets are available in 1/64 increments and in .5mm increments for metric sizes. RDA/DA collets are also known in the industry as DA and VDA collets.

I will say that Kreg does not make 1″ blue-coated pocket hole screws. The smallest size for exterior screws is the 1 1/4″ blue-coated screw. If you use picket fences, you’ll need the 1″ size for your projects, so to get the 1″ exterior screw, you will need to go to other manufacturers (I go to Armor Tools).

I am not a professional. I'm just learning as I go and trying to inspire others! I advise you always to follow manufacturer instructions, take appropriate safety precautions, and hire a professional when in doubt. I love it when you use my site for inspiration, but by using it, you agree that you do so at your own risk.

The RD/ER Collet System is the most versatile Toolholding System for any operation utilizing a round shank cutting tool in a machining or turning center. This includes drilling, milling, tapping, reaming and boring. RD/ER Collets are commonly known in the industry as ER, ESX, DR, BR, and VSAC Collets.

Centaur offers the most extensive program for ER tapping collets in the industry. ER Tapping collets will allow users to convert collet chucks used for many purposes into tapping chucks.

Measure the length and diameter of the collet. All collets have a distinctive length and diameter. Here are some common collet types and dimensions:

Older drill bits did not have these markings, and you will need to consult the manual for that jig to see how to set it up. However, I would highly recommend getting an easy-set drill bit because it makes setting up a breeze! It is totally worth it.

Rego-Fix created and patented the ER collet in 1972. The R in “ER collet” stands for Rego-Fix, representing the company’s modification to the E collet design: a groove that allows easier removal than the original E collet.

Once you understand how pocket holes work, building projects is very easy. However, all the settings and numbers can be confusing when you are just starting out.

The pocket hole jig is a drill guide that guides the drill at an angle so that you can make the pocket hole for your project.

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Anika's goal is to inspire and empower beginners with woodworking, DIY, home improvement, and home decor ideas. She wants everyone to unlock their creative potential and experience the feeling that comes with making something. Nothing feels better better than seeing something and saying "I can make that!"

Multiple Kreg Jig models are available at various price ranges, starting at $40 and going up to $400. As the price goes up, the efficiency of the jigs increases. However, they all do the same thing—make pocket holes.

The DA chuck, DA collet and DA nut must be thoroughly cleaned before assembling to maintain accuracy. A benchtop ultrasonic cleaner will dislodge fine chips and debris or, a bottle type brush can be used for cleaning the inner diameter of the collet and a toothbrush style can be used to clean the exterior. Once assembled a normal machining environment will not affect the toolholding assembly.

The newer stepped drill bits have easy-set markings for the most common thicknesses – ½”, ¾”, and 1½”. The depth collar can be moved to the required setting so the window is aligned with the marking and tightened.

Pocket hole screws come in two types of threads – fine and coarse. You want to use Coarse thread on softwoods (like pine, redwood, fir) and fine thread on hardwoods (like walnut, maple, oak).

Set the drill/driver to the drive setting and the torque to around 9-11, and drive a pocket hole screw using the special square drive bit into the pocket hole. See how to use the settings on the power drill.

More tool holders are available in ER style than TG style. ER collets are more affordable than TG collets. ER collets have better range than TG collets. Both ER collets and TG collets have about same TIR accuracy.

**You may see me or other makers put joints together without clamps but that is possible after lots of practice and being able to predict the movement of the board while being attached. ***

Removal can differ depending on the collet style used. For ER collets, hold the nut in the vertical position (diamonds/triangles in the 12 o’clock position) and press down on the collet. The collet should snap out.

The main advantage of pocket holes is that they allow you to make joints that would otherwise be impossible without advanced joinery techniques – especially an edge joint.

The countersinking conical heads on wood screws are not meant to be used with pocket holes as they will continue to drive through and crack the pocket hole.

For example, if the thickness is 1″, you want to set the collar between the ¾” and 1 ½”. In fact, you always want to err on the smaller side, so you can set it slightly toward the ¾” mark.

I am breaking down everything you need to know about using a Kreg Jig so you can start using it with confidence and build ALL THE THINGS!