Product Application To produce cuts for cylinder head bolts, hex bolts and nuts. Great for burr-and chatterless sinks in steel, cast iron, non-ferrous and light metals. Great results at low cutting speed. Grade medium for through hole Countersinking diameter 8.0 mm for M 4 Pin diameter: 4.5 mm. Shaft diameter: 5.0 mm. Overall length: 71 mm.