Drill bit shank A hex shank can be grasped by a 3-jaw drill chuck or held in a chuck specifically for hex shanks. Quarter-inch hex shanks are common for machine screwdriver bits and have spread from that application to be used for drill bits that are compatible with screwdriver machinery. The diameter of an SDS and SDS Plus shank is 10 millimeters. (The SDS Max is 18 millimeters.) The SDS shank has the advantage of fitting into a simple spring-loaded chuck, so that bits are simply pushed into the chuck without tightening. This shank and chucks made for it are especially suited to
Bit (key) Bit (key) The bit of a key is the part that actually engages the locking mechanism of a lock. (For example the tumblers in a pin tumbler lock.) The exact geometry of modern keys is usually described by a code system. This is referred to as the bitting. The bitting instructs a locksmith how to cut a certain key, to replace a lost key or make an additional copy. The bitting is usually a series of integers (e.g. 372164) that is usually translated from a key code chart or from a bitting code list to settings on specially designed key