Century Drill and Tool 69124 Premium S2 Steel Clutch Insert Screw Driving Bit, 3/16-Inch Screw driving bits made from premium S2 steel for long tool like while driving common or mild steel screws or case hardened screws Fits multiple tip hand drivers and 1/4-Inch hex holders for power driving applications always use a bit holder for power driving applications 1-Inch overall length