... all kinds of springs, including Compression spring, Extension spring, Torsion spring, Wire spring, Art and Craft spring, Battery spring ... mild steel wire, manganese steel wire, phosphorus copper wire, nickel-plated wire, zinc-plated wire, tin-plated copper wire, nickel-plated steel wire, non- ... —5,000,000 times 2.high strength of extension and hardness3.excellent elasticity4. acid and alkali-resistant ...