... CNC automatic production 5>fast delivery auto suspension coil spring 1 FactoryEstablished in 20052Trade experience Over 15 years, ... 0.55in(14mm)4Material Stainless steel, carbon steel, spring steel, alloy spring steel, refractory steel, brass, bronze, etc.5Surface ... , miniature switches, architecture, commodity and A/V equipment, hardware and plastic molds, sports equipment and gifts, and so on ...