... , Extension spring, Torsion Spring, Battery Spring, Power spring, Coil spring, leaf spring, suspension spring, etc.Main material:Carbon spring steel, alloy ... from 0.15mm to 80mm.Finish: Chromium-plated, zinc-plated gold-plated, silver-plated, copper-plated, tin-plated and nickel-plated ... plastic moulds, sports equipment and toys. Engine valve spring (with gold finish)