Material:carbon steel,stainless steel,etc. Wrie Dia:various Type: OEM/ODM Quality Approvals:ISO9001,ISO14001 Color : select Extension Spring/ Stainless Steel Wholesale Pressure spring Precision spring metal springwire diametervariousmaterialcarbon steel,alloy spring steel,music wire steel,and stainless steel,iron,plated steel,alloy steel,bronze,red bronze,phosphor copper,and beryllium copper; ...