Century Drill and Tool 69222 Premium S2 Steel Clutch Power Screw Driving Bit, 1/8-Inch Screw driving bits made from premium S2 steel for long tool like while driving common or mild steel screws or case hardened screws 1/4-Inch power drive shank fits all power screw guns cordless screwdrivers variable speed electric drills and quick change adapter 2-Inch overall length