d1 | d2 | l2 | l1 | |
BS1 | 1/8" | 3/64" | 1-1/2" | 5/64" |
BS2 | 3/16" | 1/16" | 1-3/4" | 3/32" |
BS3 | 1/4" | 3/32" | 2" | 5/32" |
BS4 | 5/16" | 1/8" | 2-1/4" | 3/16" |
BS4-1/2 | 3/8" | 9/64" | ||
BS5 | 7/16" | 3/16" | 2-1/2" | 9/32" |
BS5A | 1/2" | 7/32" | 2-3/4" | 5/16" |
BS6 | 5/8" | 1/4" | 3" | 3/8" |
BS7 | 3/4" | 5/16" | 3-1/2" | 15/32" |
When one end dulls, turn the countersink around for a fresh cutting edge. The 60° countersink angle is compatible with the profile of centers on a lathe. These countersinks have a small drill point on the tip for drilling and countersinking holes with the same tool. The drill point creates a small gap that prevents damage to the points of live or dead centers.