Abstract: A chuck includes a generally cylindrical body and a plurality of jaws reciprocally disposed in the body in communication with a central bore in the body. A first detent extends radially into the central bore and is releasable in a radially outward direction. Upon insertion of an elongated tool shaft having a polygonal cross section into the bore so that a groove in the tool shaft is aligned with the first detent, the first detent engages the groove and axially retains the tool shaft. Upon movement of the jaws so that the jaw faces engage flat sides of the tool shaft, the jaws rotationally retain the tool shaft.