BS 328-2:1972

This standard BS 328-2:1972 Drills and reamers is classified in these ICS categories:

• 25.100.30 Drills, countersinks, reamers

This Part of this British Standard gives designations and dimensions for the following types of centre drills.

1. Type A, combined drills and countersinks (centre drills) for centre holes without protecting chamfers.
2. Type B, combined drills and countersinks (centre drills) for centre holes with protecting chamfers.
3. Type R, combined drills and countersinks (centre drills) for centre holes with radius form.

Appendix A, Appendix B and Appendix C show the recommended dimensions for centre holes.

Designations and dimensions of combined drills and countersinks (centre drills) for centre holes, without protecting chamfers, with protecting chamfers or of radius form.