Overview

Most of this book has discussed using cutting tools to produce countersinks. Chapter 12 discussed pressworking techniques, which are much faster than metal cutting. The following list summarizes the majority of known means to produce countersinks. It may not be entirely complete, but it covers the majority of approaches that have been shown commercially viable.

Countersink Production Approaches

• Cutting with conventional countersink chip-making tools

• Orbital milling

• Grinding

• Coining

• Dimpling

• Powder metal pressworking

• Casting/molding

• Electrical discharge machining

• Electrochemical machining

• Laser

• Ultrasonic

• Roller burnishing

13.1 Grinding

Grinding was briefly discussed in Chapter 11 as a process used on glass and ceramics. It is also used on refractory metals and on some composites. Grinding is not widely used, but it is the only means to produce countersinks on some very hard materials and on some very abrasive materials.

13.2 Coining

Coining was briefly mentioned in Chapter 12. As a press-working process it is the same technique used to emboss the features on U.S. coins. A punch simply presses hard enough to reproduce the features on the punch into the softer workpiece. It is only used for very shallow countersinks and is not normally used on very hard or on brittle materials.

13.3 Dimpling

Dimpling was discussed in Chapter 12. It is a common sheet metal process for producing countersinks.

13.4 Powder Metal Processes

Powder metal pressing produces many of today's low cost metal products. Dies can be produced with countersinks.

13.5 Casting/Molding

Many holes are produced by casting or molding processes. Casting...