... ,M8,M10,M12,1/2",1/4",5/16",3/8"): 1.Material:stainless steel 304 or 316;or carbon steel;2.Surface treament: polished ... ;nickel plating,,zinc plating,and so on;3 ... and we will quote you competitive price asap. stainless 304 or 316 spring nut(M6,M8,M10,M12,1/4",3/8",1/2")