Abstract: An adapter member is arranged to be connected between a portion of a machine and a tool to enable quick attachment and removal of the tool to the machine. One end of the adapter member connects to the machine portion and the other end terminates in a reduced diameter section defining an annular shoulder. The tool itself is provided at one end with an entrance bore telescopically receivable over the reduced diameter section of the member so that the one end seats against the annular shoulder. The entrance bore to the tool includes a first axially directed camming surface which depresses the pin or projection when the tool is telescoped over the section. A crescent shaped groove within the bore in turn runs transversely to the axis of the bore and receives the pin or projection, the same snapping into this groove when the entrance bore is fully telescopically received over the reduced section.