An apparatus for imparting a predetermined profile to one end of a workpiece mounted on a main axis. The apparatus comprises a rotary head mounted for rotation about the main axis and at least two fingers pivotally mounted to the rotary head for pivotal movement between an open position and a closed position. Each finger has a shaping tool adapted to engage the workpiece, and a cam mounted between said at least two fingers in riding contact with an inwardly facing cam surface thereof to pivot the fingers between said open and closed positions upon relative axial movement between the rotary head and the cam.