At least 147 different designs exist for countersinking cutters. The amazing variety of countersink designs is explored in this chapter. Several sheets of thumbnail images are presented in Appendix 3 so the user may quickly visually pinpoint the tool style for which more information is desired. Every tool is given a style number, as found on the image, so its detailed description can be found easily in the pages of this chapter. In Chapter 6 Table 6.1 lists each of these styles in order by number and name so users can readily find specific tools in this chapter. In the discussion, detailed images are given often followed by tables showing the breadth of a specific tool's sizes or capabilities.

The wide variety was first documented by the author in 1996 (Gillespie 1996, 2000) and later expanded for de-burring applications to 102 designs. As a result of even more investigation the variety is expanded to the full line seen in this chapter. After an overview of the many designs, Section 3.6 describes in detail the geometries and use of each of these designs. The last section describes some products that generate their own countersink as they are installed. As a result they do not need a previously countersunk hole.