1 high carbon spring steel 2 wire Dia:0.2-8.0mm ... 4 ISO9001:2000,ROHS 5 long extension spring be made 1. MaterialCarbon steel, Spring steel, Stainless steel, Alloy steel, Oil ... -rust oil4. CertificationISO9001 Certificate, RoHS5. ApplicationsThe long extension spring is extensively used for industrial machinery,model springAutomotive, medical ... or as per customers' requirements Long Extension Spring