Drill bit shank from 0 to 7. The Morse taper allows the bit to be mounted directly into the spindle of a drill, lathe tailstock, or (with the use of adapters) into the spindle of milling machines. It is a self-locking (or "self holding") taper of approximately 5/8" per foot that allows the torque to be transferred to the drill bit by the friction between the taper shank and the socket. The tang at the end of the taper is only for ejecting the drill bit from the spindle, with the aid of a drift. The arbor of a drill chuck is often
Drill bit hand-forged carbon steel, carefully heat-treated and then hand ground to a fine edge. Spoon bits are the traditional boring tools used with a brace. They should never be used with a power drill of any kind. Their key advantage over regular brace bits and power drill bits is that the angle of the hole can be adjusted. This is very important in chairmaking, because all the angles are usually eyeballed. Another advantage is that they do not have a lead screw, so they can be drilled successfully in a chair leg without having the lead screw peek out the other