... steel with various plating 2) Head style: pan, round, flat, oval, truss, hexagon flange, bugle, wafer, hinge, binding, button, truss3) Surface ... , Tin, Ag); Painting, Powder, Anodizing, E-coating, Silkscreen, Heat treatment, Black oxid; 4) Standard/ specification: OEM service as per customers' requests ... feel free to contact us. CNC machining screw lathe screw black eletrophoresis