Gun Drill Regrind Inspection: What I Check Before Putting a Sharpened Drill Back in the Spindle
Not all regrinds are equal. I have learned the hard way that a bad regrind will cost you a broken drill and a scrapped part. A gun drill costs hundreds of dollars to replace, but a scrapped aerospace part can cost thousands. I inspect every reground drill before it goes into the spindle, and I reject about one in five regrinds from even my best sharpening vendors. Here is my inspection routine. It takes ten minutes and has saved me from countless spindle crashes, broken drills, and rejected parts. ...