How to Choose a Gun Drill Regrind Service
Problem Description A bad regrind ruins a gun drill faster than any cutting parameter mistake. I’ve sent drills out for resharpening and got back tools that couldn’t hold size for more than 10 parts. The tip geometry was wrong — the clearance angle was 2 degrees off and the drill rubbed instead of cutting. Gun drills have complex geometry: tip angle, outer clearance angle, inner clearance angle, chip breaker height, and coolant hole positioning. A regrind service that treats them like standard twist drills will destroy the tool geometry in one pass. ...