From Countersinking Handbook

3.9 Abrasive-Coated Tools for Abrasive Materials

The discussion to this point of the chapter has dealt with cutting tools and scrapers to produce countersinks and chamfers. Grinding tools can also produce countersinks and are used for hard or very abrasive materials. There are few tools available for this purpose compared to the many already discussed.

3.9.1 Style #136: Diamond-Coated Countersink

Fig. 3-166 shows a 1/2-in. diameter diamond-plated countersink having 100 grit diamond. It is officially called a "router bit" or a "countersink router bit" by its manufacturer. This particular tool comes with abrasive sizes from 100 down to 220 grit diamond particles. This medium grit diamond countersink bit is used for glass routing where a chamfer is needed. The 1/4-in. (6.4-mm) shank fits router systems and fractional collets. Diamond tool coolant is normally directed at the point of cut with this tool. The OAL of this tool is 2 in. (57 mm), the shank is 1/4 in. (6.4 mm) and the recommended speed for it is 8000 rpm.

Fig. 3-166: Half-inch diameter diamond plated countersink (style #136) (courtesy Technology LK England)

Fig. 3-167 shows a much larger diamond-plated countersink. This particular tool is built up with three layers of electroplated diamond for longer life and faster cutting. The tool is designed for countersinking operations in materials such as glass, quartz, composites, graphite-epoxy, carbon, boron, fiberglass, marble, and many other materials. Designed for use on hole diameters from 1.5 in. (38.1 mm) to 2.5 in. (63.5 mm), Table 3-116 illustrates the...

Products & Services
Countersinks are tools used for cutting angled holes or countersinks in a workpiece.
Hones and Honing Tools
Hones and honing tools are abrasive products used to refine the finish of internal bores and external surfaces.
Superabrasives and Diamond Tools
Superabrasives and diamond tools include grinding wheels, abrasive saw blades, wheel dressers, single-point tools, and other products that use diamond or cubic boron nitride (CBM) abrasive grains.
Router Bits
Router bits are rotating tools that are available in a variety of profiles and shapes. They are used with routers for edge shaping.
Wheel Dressers and Dressing Tools
Wheel dressers and dressing tools  are used to condition, true and dress grinding wheels. Dressing is the process of re-sharpening the tiny cutting edges on a grinding wheel’s surface.

Topics of Interest

3.10 Unusual Configurations A few configurations are unusual, used in only a single application or while not applicable today are interesting to note for historical reasons. Some of these are...

3.6 Detailed Countersink Discussion Countersink tools are discussed in detail in the following paragraphs of this chapter. They are presented in numerical sequence of style number. A generic name is...

3.2 Typical Countersink Cutter Materials Material choice for countersinks is critical for economical tool life. The most common materials used are listed below and the effectiveness of any of them...

3.4 German versus U.S. Countersink Standards and Practice The German institute Deutsches Institut f r Normung e.V. (DIN) develops standards for German industry. It has four countersink standards,...

Previous chapters dealt primarily with conventional workpiece materials such as aluminum and steel. Other metals were discussed and speeds and feed data were presented for several metals. The...