http://www.yugoodhw.com/springs/ Our compression springs are widely used in electronics, motors, computers, digital products, automobiles, bicycles, hardware tools, gifts, toys and other fields. Material: stainless steel, carbon steel, customized. Coating: Galvanized, Nickel plating, Anodic oxidation, Black oxide, etc. Certificate: SGS, ROHS. Grade: A2-70/A4-80.