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Tool manufacturers have always chased the elusive dream of tools that stay sharp longer. It’s their El Dorado, their Fountain of Youth – a great theory, but mired in myth. You can’t take metal that is soft enough to form and sharpen, and then whack it violently into dense composites such as MDF all day long and not expect it to wear away. Unless, of course, you’re not relying on metal.

Which raises the question – are diamonds a woodworker’s new best friend?

Polycrystalline diamond (PCD) tools have been around for about 40 years and they’re gradually finding a larger place in woodworking. They’re best suited to long production runs in a single material or sheet type. They cost more than carbide but, of course, diamonds hold an edge for an incredibly long time when working on abrasive materials. That’s the key here. Diamonds are abrasive; they wear rather than cut or slice. They do that because the tiny particles have sharp edges that are not lined up uniformly like the teeth on a saw blade. They point in every direction.


One advantage to PCD is that it can be graded and used by size, so it’s possible for manufacturers to supply fine, medium and course abrasives. That means that one size doesn’t need to fit all. It’s possible to tweak a shop’s diamond tooling to best suit materials such as natural wood, particleboard, MDF, and even solid surface countertop material. For example, PCD is well-suited to cutting laminate flooring.

Diamond CNC tools are available as tips, inserts or complete tools depending on the geometry. The word to keep in mind here is hardness. PCD is extremely hard and resistant to wear, but that means it can be brittle, too. It’s also relatively impervious to heat build-up, and it offers low friction. Those characteristics mean that a woodshop can feed material to a PCD cutter much faster than it can to a carbide tool.

When it comes to cost, the way to compare tools is to count the number of cuts that each can make, or the linear feet of machining done. A diamond tool may outlast a dozen or more tungsten carbide ones, so there’s a lot less time spent changing out bits. Coarse PCD cuts faster but is more susceptible to chipping and breaking than fine grades, and it can leave a little tear-out. Fines produce a cleaner edge, so there’s a trade-off between volume and quality. Manufacturers are beginning to offer shear angles that can be used in finish cuts to deliver a polished, smooth surface in MDF. That’s a second cut, where a coarse tool has already hogged parts almost to size and the clean-up is being done after a tool change, or perhaps on another machine. Using a very fine PCD tool is a way to hone joinery or shaped edges and reduce sanding.

One of the challenges with advances in tooling is that there are usually concurrent advances in the panel materials being cut. What has been working well for plastic laminates or foil may not continue to do so if the panel substrate or coating changes. Diamond tools that have been tweaked to create crisp edges may deliver less than spectacular results when a shop changes suppliers or adds new sheet stock. Unfortunately, a woodshop needs to inspect and experiment to keep ahead of the curve.

The geometry of PCD router bits, especially compression bits, is also evolving quickly. If you gave up on disposable diamond bits a few years ago, it may be time to take another look.

Yes, diamonds are expensive initially. But over the life of the bit, they can be very inexpensive when one tallies up the linear feet that they machine.


Coatings on carbide

Short-run woodworking in smaller shops is perhaps better served by carbide tooling. Carbide bits will wear faster but they can deliver a better edge, and they are more affordable. Smaller woodshops don’t often run a CNC day after day that is making the same cut over and over. Technology has delivered some advances here, and those take the form of better carbide, improved geometry, and high-tech coatings that provide some protection and wear resistance.

For example, Freud Tools ( has recently added Black Ice coating, which is designed to deliver a cooler cutting edge and superior chip evacuation. Freud says it’s the industry’s first functional coating, and that it protects carbide edges by creating a slick, lubricant-like action. When combined with the company’s TiCo solid carbide, Freud’s triple-flute compression spirals can deliver twice the life and performance of standard double flute bits in double-sided panels. When the transition between up-shear and down-shear flutes is centered in the workpiece, these tools produce a perfect finish on both the top and bottom surfaces of panels, according to the company.

Amana Tool’s ( Spektra Extreme coating (nACo) is a micro-thin ceramic coating that lets a CNC tool’s cutting edge retain crucial sharpness and lubricity. It prevents high heat and oxidation, which are detrimental to cutting tool performance. These tools are instantly recognizable because of their multi-colored hues which, while attractive, will dissipate upon use. However, the coating will remain fully effective, according to the company.

CNC-Tool ( offers solid carbide router bits with a diamond coating that is designed to retain crucial sharpness and lubricity. The company says the coating prevents high heat and oxidation build-up that is detrimental to cutting tool performance, and it shields the cutting edge from hard-wear materials.


Bits & Bits ( manufactures CNC tools with Astra Coating, a multi-layered surface coating that allows faster speed and feed rates, reduces dust and pitch build-up, and can be easily cleaned with solvents, according to the company. Bits & Bits is the only factory-authorized distributor to offer Astra Coated Whiteside router bits, and these tools can be sharpened just like standard carbide tools.

Many other leading CNC tool manufacturers offer coatings that enhance performance, so it’s worth checking catalogs to see if the profile you need is offered with this type of upgrade.

Finding CNC tooling

There are thousands of tool suppliers around the world, and many of them sell products in North America. Finding a company that fits perfectly with a woodshop’s needs can take a lot of time and patience, but it can also be very rewarding. Knowledgeable salespeople and custom CNC tooling are great assets, and it’s also nice to have an established relationship when the supply chain gets a bit wobbly as it has recently.

GDP Industrial Tooling offers a CNC Tooling Guide at that answers most common questions and delivers basic tooling information for newcomers to CNC machining. It helps woodworkers become familiar with all the options available (including toolholders), plus the differences in tooling types as well as the pros and cons of each.


W. Moore Profiles ( has locations in Florida and North Carolina and the company offers a wide range of CNC tools, including custom manufacturing. Georgia-based US Router Tools ( carries a large inventory of CNC tools from Southeast, Amana and Onsrud.

Peak Toolworks ( is the parent company of several familiar brands including NAP, GLADU, General Saw, RKO and Riverside Tool Corp. The company offers both carbide and diamond router bits, and it can manufacture to unique designs or match an existing profile. Peak provides router bits for high-volume manufacturing in wood and wood-based materials, including nesting operations.

Among the latest innovations from Vortex Tool Co. ( is a selection of roller bearing tightening stands for ISO, HSK63F and BT30 toolholders. Vortex manufactures a full range of custom cutting tools, and also distributes major brands including Bosch, Bimex, Everlast, DML, Forest City Tool, Leuco, Onsrud, Terminus, W.L. Fuller and Wisconsin Knife.

When it comes to large profile cutting on a CNC, Leitz ( offers a number of solutions including the ProfilCut Q tool system that can combine carbide and diamond cutters to offer a very customizable solution that includes both disposable and resharpenable options.

Custom tooling manufacturer Charles G.G. Schmidt & Co. ( also offers a line of solid carbide CNC bits, spoil-board cutters, CNC toolholders and arbors, collets and nuts, corrugated back router heads and knives, and diamond-tipped PCD router bits designed for particleboard, MDF, plywood and plastic.

Another custom manufacturer, Comsurge Tooling (, has a full catalog of industrial grade router bits.

Freeborn Tool Co. ( is headquartered in Spokane, Wash. and features brazed, insert and custom tooling options for shapers in its extensive catalog. The company also offers router bits.

CMT Orange Tools ( carries an expansive collection of CNC tools, which are intermixed with collets and chucks on the company’s website. They include everything from spoil-board surfacing to ball nose spirals, up and down cuts and insert bits. Padsmore ( is the distributor for CMT in Canada.

Spektra Extreme from Amana Tool.

Spektra Extreme from Amana Tool.

Makita ( and Grizzly Industrial ( carry a wide selection of router bits for precision edge finishing, joinery, trimming, groove-cutting, and more. Eagle America ( now carries more than 2,000 different bits, including sign-making and straight bits.

Infinity Tools ( in Oldsmar, Fla. carries most of the major brands and also offers its own proprietary line of router bits. The company sells router bits individually and in sets, plus shaper cutters, carbide sawblades, stacked dado blades, planer knives, jointer knives and insert tooling.

The Leuco ( catalog includes some interesting technologies including the Modula system for small diameters and high feed rates. It includes HSK 63F tool adapters, spacers, plus turnover and profile knives. 

CNC tooling gets dressed up with abrasives, protective coatings and more.

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