... standard oil tempered spring steel wire Grade:55CrSi,60Si2Mn,65Mn Dia:6.0~16.0mm Standards: ASTM, BS, DIN, GB, JIS ASTM standard ... oil tempered spring steel wire Grade:55CrSi,60Si2Mn,65Mn Dia:6. ... . Marerial: we select good quality spring steel wire rod.2. Surface treatment: advanced technology of shot ... 16501630~17801740~18903540 ASTM standard oil tempered spring steel wire