... 3 coloured zinc plated 4 ISO9001:2000,ROHS 5 long extension spring be made 1. MaterialCarbon steel, Spring steel, Stainless ... coating,cataphoresis,anti-rust oil4. CertificationISO9001 Certificate, RoHS5. ApplicationsThe long extension spring is extensively used for industrial machinery,model springAutomotive, medical ... bags and outer cartons or as per customers' requirements Long Extension Spring