Pilots for Counterbore Used with counterbore for guiding counterbore when drilling recessed holes into scales for Corby Bolts, Gulso Bolts, screws etc. Pilot Head size should match diameter of hole drilled through tang (1/8"-1/4"). Shank size should match counterbore pilot hole size (i.e. 3/32" or 5/32"). Material- High speed steel Counterbore 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 Drill Bit Note To drill holes in knife handles to use with piloted counterbores for fasteners, it is recommended to use the letter/number size slightly larger than the pilot size: with 1/8" pilot use at #30 bit, for 5/32 pilot use #22, for 3/16" use #11, for 1/4" use F. This will ensure that the pilot does not bind up in the material and break off or pull out. We have these bits available in the Killer Force Drill Bit listing.
