Counterbore

High speed steel straight shank

Used for drilling recessed holes into scales for Corby Bolts, Gulso Bolts, screws etc.

Counterbore pilots must be purchased separately. 

Selection Guide:

Corby bolts-

3/16" uses Counterbore #CB1 with Pilot #PIL1

1/4" uses Counterbore #CB2 with Pilot #PIL2

5/16" uses Counterbore #CB3 with Pilot #PIL3

Gulso Bolts-

1/4" uses Counterbore #CB2 with Pilot #PIL5

5/16" uses Counterbore #CB3 with Pilot #PIL2

3/8" uses Counterbore #CB4 with Pilot #PIL4