... M42&Length 6-200MM 2.Material:carbon steel 3.Plain:Black Oxile. din934 hex nutfeatures:1.standard:hexagon nuts din934 ... Our main products are bolts, screws, nuts, machine screws, plain washers, spring lock washers, wood screws, tapping screws, drilling ... , brass or other special materials. For finishing, we provide black oxide, zinc electroplating, phosphate, copper plating, mechanical galvanization, ...