... 3 coloured zinc plated 4 ISO9001:2000,ROHS 5 Automotive,machine 1. MaterialCarbon steel, Spring steel, Stainless steel, Alloy steel, Oil ... tempered wire2. Wire diameter0.2mm-8.0mm3. Surface Treatmentzinc,nickel plated,become black,powder coating,cataphoresis,anti-rust ... outer cartons or as per customers' requirements Compression Spring for Machine