drill bits

Drill bits are cutting tools used to create cylindrical holes. Bits are held in a tool called a drill, which rotates them and provides axial force to create the hole. Specialized bits are also available for non-cylindrical-shaped holes. The twist drill bit is the type produced in largest quantity today. It can be used to create holes in metal, plastic, wood and stone. Center drill bits are used in metalworking to provide a starting hole for a larger sized drill bit, or a conical indentation in the end of a work piece to mount a lathe center. These centers are used when turning or grinding work pieces. A core drill bit (as pictured) is used to enlarge an existing hole. The existing hole may be the result of a core from a casting or a stamped (punched) hole.