“New tool geometries, dust removal attachments, hydro, heat-shrink, or even improving the quality of standard tool holders all play a role in the elimination of unnecessary tolerances at the cutting edge, which, not only provides a cleaner surface finish, but equally important, will reduce overall tooling cost. Many folks shy away from upgrading their cutting tools because of initial expense without giving a second thought to the cost savings they will experience over the life of the cutting tool,” she added.

Deutschler added, “Heat-shrink or power shrink tool holders are my preferred tool holder option for insert tooling. The tool body will never need to be removed from the holder as the cutting inserts are simply replaced when dull, and therefore, no accessories are needed. The tool is delivered already mounted and balanced on the holder.” For those using standard tool holders, she recommended that the collet be replaced every 500 machine hours.

Not only is this relevant to woodworking, but other industries as well, said Marc Wijtenburg, T-Tool USA owner. “We have seen an increased demand for tooling used in the aerospace industry with the main focus on nonferrous materials. Several U.S.-based OEM machine builders whose core business segment is primarily woodworking and plastics have ventured into this market segment.”

As a result, Cogsdill’s tools are better suited to high production lines, an area that has seen some big changes of late. Only a few years ago, small bores were typically 4 mm, but now leading vendors are delivering off-the-shelf bore grooves to 2 mm, with specialty applications going much smaller. This has resulted in new abilities—and challenges—when it comes to grooving very small parts, as well as increased demand.

Horvath agreed. “The synergy between the cutting action produced by the tooling and the machine has become a much greater focal point in the last two to three years,” he said.

The use of clamping systems, such as heat shrink, mechanical shrink and hydraulic, was also addressed by many, with Michel stressing their use for high volume tool applications.

Serwa agreed. “Tool holding and clamping is an extremely important factor in achieving optimal machining results and is often overlooked as a source of increasing machine performance.”

Options are available that can significantly increase clamping force over standard systems and improve production, “By increasing the clamping force and accuracy of the holding system, users will see less tool vibration, which results in the ability to increase feed rates, extend tool life and extend spindle life,” Serwa added.

When grooving small pieces, cutting pressure tends to be relatively high. Aside from slowing feed rates, it can also help to use high lubricity coolants that work well in tight spaces.

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“The challenge with grooving is that below 1.5 mm it is difficult to make a tool that is strong enough,” says John Stewart, VP of engineering at Bokum Tool in Madison Heights, MI. “The overall determining factor is: What does a groove look like in a hole that size? If it is proportionally very similar to a larger hole then it is theoretically possible to get very small, but it really comes down to the strength of the tool itself.”

How best to approach grooving a small part has a lot to do with the materials involved: repeat, high volume applications tend to be with softer metals, with specialty one-offs applying to higher value applications, often with tougher alloys.

ID grooving in particular can be an issue with small parts, says Steve Geisel, senior product manager for Iscar Tools Inc., Oakville, ON.

Another approach is to compress chip width, thus ensuring it doesn’t lodge in the groove and result in tool failure. Either way, when it comes to grooving small parts, the combination of slow feed rates, proper tool selection, and a strategy for chip evacuation is the best way to ensure success.

Alster added, “Tool holders provide the critical link between the machine spindle and the cutting tool. Minimizing tool deflection and maximizing tool concentricity divides the workload evenly across all cutting knives, thereby optimizing cut quality and machine throughput by a factor of at least 30%. Tool rigidity and concentricity also improves tool life by a factor of at least 30%.” He continued, “Heat shrink systems can be integrated alongside existing chuck systems, so primary routing activity can be optimized while maintaining flexibility for more obscure applications.”

“Slow feeds can be a good idea, depending on the material,” says Bokum Tool’s Stewart. “With smaller sizes a weaker tool neck will want to deflect, especially with carbide, and with increased distance to the groove, feed speeds need to be adjusted downward.”

“The geometries are not standardized, but there are ways to create space at the head of the tool to promote chip flow,” says Stewart. “Sometimes the actual grooving tooth on the cutting tool will have a chip breaker on it—this will help the chip move out and get flushed with coolant.”

A bit of tooling knowledge can go a long way toward improving the productivity of CNC routers and machining centers in a woodworking plant.

Scott Feimster, vice president Sales & Marketing at LMT Onsrud, added, “We analyze the material, identify its challenges and develop a solution with a combination of [tool] substrate, cutting geometry, coatings and cutting technique.”

“The grades Iscar uses for our inserts depend on how fast the machine spindle can spin,” says Iscar Tool’s Geisel. “10,000 rpm sounds high but remember you are working with very small parts, around .100 in. in diameter. So that 10,000 rpm with a .100 in. diameter works out to be about 260 sfm…we need to design and produce the insert out of carbide grades with coatings that can run at such speeds.”

“This is terrific as the quality of tool holding has a direct correlation to surface finish, accuracy, tool life and changeover downtime that will provide cost savings but also and more importantly improved product quality. Balancing requirements, specifically the target of G2.5 at 18-24,000 RPM has become more frequently demanded by machine manufactures and end users alike. This, in conjunction with improved tool holding, is providing dramatic improvements to production and enables our customers to be even more competitive,” Horvath added.

“The biggest change I see is the hardness of the carbide. We are continually working with the carbide companies to improve on and develop harder and more-wear resistant grades of carbide,” said Chuck Hicks, president of Southeast Tool. “But, this has its challenges, with the harder carbide means the customers are going to have to stay on top of feeds and speeds and change those collets regularly. The higher grades of carbide are so hard it’s extremely fragile and breaks very easily so machine maintenance is a must.”

“You need the chips to be able to freely get out of the bore and away from the cutting action so they do not interfere with the machining process.”

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He added, “Even though the materials look the same they will oftentimes react differently when being machined.” A site visit can also determine if there is another cause for the problem.

The problem with carbide is that reducing deflection increases the risk a tool will break, so it’s important to preserve the strength of the neck of the tool. Tool monitoring is also recommended, because with small cutting edges it can be hard to see or hear when a tool breaks.

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Frank Horvath, marketing manager at FS Tool Corp., also commented on the demand for improved dust extraction on the cutting tools, particularly within the CNC routing cells. “We are responding by investing heavily in the research and development of new technologies.”

In today’s competitive marketplace, tool manufacturers are often tasked with increasing the machine performance. Choosing the correct tool holder for the job is integral to achieving this.

Ron Migedt, CEO of Riverside Tool Corp. commented on the “continual addition of low emission adhesives and other fillers into the material” along with new materials being used by wood products manufacturers. “Both of these material developments are demanding more advanced tooling in order to produce the product with acceptable quality.”

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“There are companies that require face grooves with major diameters as small as 0.2 mm,” says Duane Drape, national sales manager for Horn USA Inc., in Franklin, TN. “This is mostly aluminium, but I have had customer requirements to get that small with steel at 50 + Rockwell.”

“You have to run balanced tools,” Migedt said simply. “We are seeing an increased need for highly accurate tool-holding technologies that can provide the support that next generation tools demand; for example an extreme-shear tool will require the best tool-holding to reach its potential. There have been innovations in user-friendly tool-holders with high-clamping pressure that have enabled customers to easily achieve the tool-holding needs that today’s tools are requiring.”

But replaceable inserts, single edge, can still get to some small diameters. More cost effective than a solid carbide tool, they can also deliver better axial depth. That said, solid carbide tools are usually more expensive, toolholders aren’t, and there is a risk the holder might break after a dozen or so uses.

“The cutting process produces pressure on the work piece and on the tool. Controlling the pressure during machining dictates how successful we will be [in producing an effective cutting tool]. We can control cutting pressures by controlling the width of the grooving insert; the wider the insert, the more pressure it will produce. We also grind positive rakes on the inserts to control the pressure and to act as a chip former to control the chip shape and size.”

Wijtenburg also noted that “Spindle suppliers are now offering more HSK-63A taper tooling to the OEM machine builders giving the end user more tooling options,” whether machining wood, metal or other materials.

Tops on the list of items impacting today’s router bits is the substrates to be machined. No longer are woodworking operations cutting strictly solid wood or wood-based panels, and changes in tool composition and geometry are reflecting this.

He adds, “Now more than ever we are designing tools with the entire product in mind. We work with customers to find out the machine, material, and all factors involved with producing the product. We have advanced our tool designs by innovating with new geometry, such as shear, to achieve the cut quality and chip evacuation needed to meet the customer’s expectations. We have also advanced universal tool technologies, such as multi-profile insert tools, to help customers meet the demands of quick-delivery and small batch sizes.”

“If you are cutting to small major diameters on the face, where the grooves generally aren’t that deep, the chips are not an issue,” says Drape. “But in ID grooving applications where the groove is deep into a bore, then we need to get coolant in, and also need to break down the chip so it can evacuate.”

A frequent issue is whether or not to go with inserts or solid carbide tools. Inserts can be indexable or have only one edge for single use. Inserts tend to be less expensive, but usually can’t get into the smallest bores, and are not as strong as solid-carbide tools.

He continued, “The foundation of tool engineering is understanding the cutting challenges to define the best substrate. Today’s advanced coatings offer heat resistance and protect the cutting edge of the tool to maximize the return of your highly engineered cutting tool.”

Solid carbide grooving tools are usually L-shaped. Part of the challenge is that even the non-cutting, or “leg” part has to fit into the bore diameter. Given that the bottom of the L, or the “foot” has to be even smaller, strength becomes an issue, as does the fact that groove depth is limited. As a result, with bores of less than 2 mm in diameter the best tools are now constrained to a groove depth of around 0.2 mm.

Bob Barone, sales manager at Benz Inc., agreed. “I think the ever-widening arena of ‘Engineered Materials’ is the driving force behind new tool design. More and more materials are crossing over between industries today. Classic woodworking shops are now processing plastics and composites as a result of changing architectural specifications. The dust generated by these materials must be removed from the shop atmosphere in accordance with the regulating agencies. Typical dust hoods on machinery do a fine job for wood particulates, however with engineered materials we are constantly pressured to design tool holders and aggregates that aid in expelling the dust precisely at the source.”

“This is a double-sided insert that works well with slow cutting forces,” says Kaufmann. “The GUP insert geometry is advanced and versatile, with excellent metal removing rates.”

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Barone also noted increased requests for “very dedicated CNC aggregate tool holders designed specifically for a single task. This typically is to eliminate an operation off-line from the CNC machine.”

“Manufacturing the tool correct from the beginning is a must,” added Hicks. “Then we must have the operators keep up the maintenance on the machine.”

“The most advanced cutting tool in the world in a worn and inaccurate tool holder just became the most advanced, worn and inaccurate tool available. Maximizing the accuracy and rigidity of your tool presentation will result in higher productivity, longer tool life and better quality cuts. If you purchased a three flute tool………you want all three flutes providing a finish cut and all three doing an equal share of the work,” Feimster said.

Hydraulics, given their need to control pressure, create demand for inside diameter (ID) and outside diameter (OD) grooving seals and threads, as well as relief grooves. In the automotive sector, miniature grooving applications include fittings for air bags and fuel injection components.

Geisel concurs with John Stewart that the challenge for tooling suppliers is to make a strong, rigid cutting tool or insert.

“Tool life and cut quality are sometimes affected negatively when switching to a new material,” said Mike Serwa, vice president at Vortex Tool Co. Inc. “Oftentimes our customers are forced to switch materials either because of cost savings or because of supply issues.”

“Exotic materials are not for production jobs—these are low volume applications,” says Tom Ficker, regional sales manager for Cogsdill Tool Products, Inc., with responsibility for Canada. “The problem with precision grooving in high nickel alloys is that you beat down on the grooving insert almost from the get-go.”

If the chip created by the grooving tooth is wider than the finished groove, then you can minimize the possibility that the chip will stay in the groove. But when it comes to harder metals the challenge isn’t chip control so much as creating the chip in the first place. “At 1.5 mm you need to have a tool that is strong enough to create the chip,” says Stewart. “But from there, with a strong alloy like Inconel, it is relatively easy to control the chip. In the case of aluminium and softer materials, where the chip is continuous, it creates greater headaches because the material balls up.”

“As a tooling manufacturer, we are being pushed to produce tooling able to groove in smaller, and smaller diameters. Our PICCO line can produce grooves in diameters from as small as 2 mm (.08 in.) and we can go smaller by special request.”

“If there ever was a time to say ‘You get what you pay for, this is it,” added Barone. “To my customers I say; ‘Buy good machinery, learn how to use it and all of the features you paid for and most of all, partner with a good tooling supplier.’ One that will work with you to find the best tooling product for your application.”

Tool balance and concentricity are critical to achieve quality products noted a number of manufacturers, including Hicks, Michel and Migedt.

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Along with FS Tool, a number of companies, including Royce//Ayr and Leitz, also offer dust extraction systems that move dust and chips away from the cutting tool, thereby reducing heat and “secondary collision damage to the tool.” ”Several tool manufacturers have recognized the benefits associated with improved dust extraction and collection, such as reduced heat build-up, reduced tool damage, and reduced machine downtime due to tool changes and machine clean-up,” said Mark Alster, regional manager at Leitz Tooling Systems LP.

“It would be preferable to take an indexable insert into small grooves, because it would be more economical. But you often have to go with a one piece design, using a brace tool with a carbide or carbon steel cutter brazed to it.”

“It is important to keep speeds as low as possible when you have small-sized parts,” says Igor Kaufmann, a member of Kennametal Inc.’s global team for turning tools. When grooving miniature parts, Kaufmann emphasizes that the tools still need to fit axially and apply radial force to the bore. As a result, it is hard to ensure that the tool is strong enough, which then leads not only to chatter issues but also challenges with breakage and chip evacuation.

Managing chip generation in tight spaces has always been a challenge, because the smaller the hole the harder it is to get the chip out. One approach is to plum or port the tool to get coolant out. There are also advanced tools, like Kennametal’s AF-GUP insert geometry for grooving and turning, that are specially designed for these challenges.

Karin Deutschler, president of GUHDO USA, added. “Tooling manufacturers have to look at all aspects that affect the performance of a cutting tool. There is a synergy between cutting tool, collet, tool holder, chip evacuation, spindle speed (and accuracy), feed rate and, of course, the material being machined, and all this must be considered when finding solutions.

“The variety of materials machined by our customers has grown significantly over the last few years. Not only do we see changes in the substrates or core materials but also in the variety of laminates and surface treatments themselves,” said John Michel, director of Sales and Technical Services at Leuco Tool Corp. “Some materials are more abrasive, some more brittle, and some are very challenging to machine acceptably. Today’s tooling manufacturers must address the variety of these materials while at the same time not requiring customers to have a special tool for each material type.”