We used austenitic stainless steels,the chemical composition including carbon,ilicon, manganese, phosphorus etc SpecificationsStainless Steel U bolt 1.Material: Stainless steel 316 or stainless steel 304 or steel 2.Surface:zinc, nickel,galvanized3. Certificate: ISO 9001:2000 1) Material :steel, carbon steel, stainless steel2) Surface treatment: Zinc plated,power coated,chrome plated,hot dipped ...