Drill bit shank in drills meant to reach into very tight spaces, and threaded countersink cutters are widely used (along with finely adjustable depth stops) to create holes which put a matching rivet directly flush with the surface. Drill bit shank The shank is the end of a drill bit grasped by the chuck of a drill. The cutting edges of the drill bit contact the workpiece, and are connected via the shaft with the shank, which fits into the chuck. In many cases a general-purpose arrangement is used, such as a bit with cylindrical shaft and shank in a three-jaw chuck which
Drill bit insertable tip, called an insert. The inserts come in various sizes that range from . The tool holder usually has a coolant passage running through it. They are capable of cutting to a depth of about 10 times the bit diameter. This type of drill bit can also be used to make stepped holes. Straight fluted drill bits do not have a helical twist like twist drill bits do. They are used when drilling copper or brass because they have less of a tendency to "dig in" or grab the material. A trepan, sometimes called a BTA drill bit (after