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 in general construction. One drill bit can drill the entire range of holes necessary on a countertop, speeding up installation of fixtures. They are most commonly used on softer materials, such as plywood, particle board, drywall, acrylic, and laminate. They can be used on very thin sheet metal, but metals tend to cause premature bit wear and dulling. Unibits are ideal for use in electrical work where thin steel, aluminum or plastic boxes and chassis are encountered. The short length of the unibit and ability to vary the diameter of the finished hole is an advantage in chassis or front