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 and the rotating flutes carry away the dust. Rotating the bit also brings the cutting edges onto a fresh portion of the hole bottom with every hammer blow. Hammer drill bits often use special shank shapes such as the SDS type, which allows the bit to slide within the chuck when hammering, without the whole heavy chuck executing the hammering motion. Masonry bits of the style shown are commonly available in diameters from 3 mm to 40 mm. For larger diameters, core bits are used. Masonry bits up to long can be used with hand-portable power tools, and are very