... .0mm Standards: ASTM, BS, DIN, GB, JIS ASTM standard oil tempered spring steel wire Grade:55CrSi,60Si2Mn,65Mn Dia:6.0~16.0mmStandards: ASTM ... , DIN, GB, JISAdvantage:1. Marerial: we select good quality spring steel wire rod.2. Surface treatment: advanced technology of shot blasting, 100 ... .50~7.001430~15801400~15501500~16501630~17801740~18903540 ASTM standard oil tempered spring steel wire