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 sizes in 1959. A comprehensive table for metric, fractional wire and tapping sizes can be found at the drill and tap size chart. Metric drill bit sizes define the diameter of the bit in terms of standard metric lengths. Standards organizations define sets of sizes that are conventionally manufactured and stocked. For example, British Standard BS 328 defines sizes from 0.2 mm to 25.0 mm. From 0.2 through 0.98 mm, sizes are defined as follows, where "N" is an integer from 2 through 9: From 1.0 through 2.95 mm, sizes are defined as follows, where "N" is an integer from 10