Aircraft Counterbore - Aircraft Counterbore, 5/16'''', Piloted

Piloted counterbores allow you to accurately drill stocks with existing screw holes for pillar bedding, with no fear of the cutter wandering. Interchangeable pilots provide increased versatility, allowing two cutters to do the work of six. Makes adding pillar bedding blocks quick and easy. Pilots and cutters available in popular sizes to accommodate most bedding needs. Mfg: Brownells SPECS: Counterbore: HSS Steel, 1/4" (6.3mm) shank. 9/16" (14.4mm) cutter, 1/8" (3.1mm) pilot hole. 2-13/16" (7.1cm) long. Pilot: Carbon steel, 1/8," (3.1mm) shank, 1/4" (6.3mm) and 5/16" (7.9mm) diameter.