... , screws, nuts, rods, studs, washers and many other hardware products, made of carbon steel ... , alloy and stainless steel, aluminum, brass or other special materials. For finishing, we provide ... black oxide, zinc electroplating Cr+3, phosphate, mechanical galvanization, hot dip galvanization, Dacromet and ... .9, A2-50, A2-70 and A4-70etc standard and non standard nut