Abstract: A rotary power driven portable hand tool having a simplified torque responsive clutch assembly. The clutch includes a spindle having a radially outwardly extending flange, a clutch carrier rotatable about the flange, the clutch carrier carrying a plurality of clutch balls which are forced into engagement with one face of the flange by a compression spring being held in place by adjustable spring retaining means carried by the spindle. In one embodiment the face of the flange contacted by the balls is provided with a cam surface having a plurality of spaced apart recesses, there being a washer interposed between the balls and the end of the spring adjacent the balls. In a second embodiment a sleeve member is keyed to the spindle and is disposed between the compression spring means and the clutch balls, the sleeve member being reversible and having cam surfaces of different ranges on its opposed faces, one of which faces engages the balls to hold them against the face on the flange formed on the spindle.