... 3.wire diameter: 0.09mm-6.00mm 4.high precision 2012 Newest Drawing Steel Compression Spring1) main material: carbon spring steel ... -resistant alloy and bronze.2) Finish: chromium-plated, zinc-plated, gold-plated, silver-plated, copper-plated, tin-plated and nickel-plated, painted, spraying powder, coloring3) the quality management ...