A precision work holding chuck which centres finished round stock automatically when tightened.
It has flexible sides that allow the collet to be compressed slightly and secured around a tool or workpiece. The collet has a similar function to a chuck, but can accommodate only a narrow size range.
Typically provides greater gripping force and precision than a chuck as the jaws of the collet are applied around the complete circumference apart from thin slits between the jaws.
See also: Chuck.