... 0.01mm tolerance 4.QC inspect after products finished 5.brass screws A:certification: ISO9001:2008B.Products Available bolts, screws ... , nuts, rivets, Heatsink, shafts(axles, spline shafts, dart shafts),gears (pinions, wheels ) bearing, LED light-fixture, auto parts, electronic ... , SS304, SS316 etc.2. Steel:Q235,20#,45# etc.3.Brass:C36000 ( C26800), C37700 ( HPb59), C38500( HPb58), C27200(CuZn37), ...