Even if you’re not building an airplane, you probably have need to bore holes in metal from time to time. In this continuing series by our sister publication KITPLANES, Paul Dye explains the finer points of using a step drill, sometimes also called a UnitBit. Basically, it makes a big hole out of a smaller hole and is especially handy when you don’t have very large drill bits for metal. (Few of us do.)
Those things are great. They also work well using them in a drill press. I couldn’t have finished my plane without a selection of those things.