Abstract: A tool holding fixture having a rotationally symmetrical holding body and a shaft that form one piece. The one piece has an axially directed first annular groove which is concentric with the shaft and is positioned in a transition area between the holding body and the shaft. The shaft has an annular collar with a flank which is inclined in a direction toward the first groove. The rotatable clamping ring encompasses the collar and engages the first annular groove. The rotatable clamping ring is seated on the shaft. The clamping ring has a second annular groove in which wedge-shaped sliding blocks are seated and are radially and axially moveable, but secured against canting within the second groove. The sliding blocks are supported on the inclined flank of the collar. A pressure screw is threadedly engaged within the clamping ring.