Vermont American 14455 - 5/16-Inch Self Feed Spade Bit Black oxide standard length spade bits Bits are 6-Inch/150 mm long and feature a 1/4-Inch quick change hex shank with power groove Featuring the fast-feed threaded tip Threaded tip pulls bit through 3x faster than a standard spade bit Quick change, flatted shank for easy bit changes and secure grip