Milwaukee® Left Hand Thread Socket Head Cap Screw measuring 1/4" -20 X 1" is designed for hammer drill, electric drill, 1/2" reversing drill, 1/2" electric drill, 1/2 inch reversing compact drill, magnum two speed hammer drill, drill, cordless drill / driver, cordless 18 V keyless 1/2" D-handle drill, drill press, single speed hole hawg drill, two speed hole hawg drill, electric drill / driver, hammer drill, electric drill.