... 4>CNC automatic production 5>fast delivery auto suspension coil spring 1 FactoryEstablished in 20052Trade experience Over 15 ... 55in(14mm)4Material Stainless steel, carbon steel, spring steel, alloy spring steel, refractory steel, brass, bronze, etc. ... kinds of cars, machinery, home appliance, electronic products, electric appliance, stationery, computers, power switches, miniature switches, ...