Machine taper

Drill chucks mounted by Jacobs tapers onto arbors with Morse tapers for the spindle.
Spindle nose on a lathe headstock. The small female taper is a Morse taper to take a lathe center or a tool such as a twist drill. The large male taper takes a lathe chuck, which is retained by the large nut.

A machine taper is a system for securing cutting tools or toolholders in the spindle of a machine tool or power tool. A male member of conical form (that is, with a taper) fits into the female socket, which has a matching taper of equal angle.

Almost all machine tool spindles, and many power tool spindles, have a taper as their primary method of attachment for tools. Even on many drill presses, handheld drills, and lathes, which have chucks (such as a drill chuck or collet chuck), the chuck is attached by a taper. On drills, drill presses, and milling machines, the male member is the tool shank or toolholder shank, and the female socket is integral with the spindle. On lathes, the male may belong to the tool or to the spindle; spindle noses may have male tapers, female tapers, or both.