SK Hand Tool 813 13mm Standard Drive Socket Turbo 3/8-Inch Sk Sockets slotted and Phillips head screws too tight for a screwdriver. Even screws, nuts and bolts with very thin, rounded or tapered heads Even screws, nuts and bolts with very thin, rounded or tapered heads can be removed. Variety of styles and sizes are also available Also removes a wide variety a wide variety of other problem fasteners like oil pan plugs, corroded marine nuts and bolts and manifold nuts