... ,202,304,304HC,304L,310S,316,316L,317L Surface:bright,polished,black Certificate:ISO,SGS Origin:China Material Name: ... and application scope:Is widely used silicon manganese spring steel, strength, elasticity and its quench-hardening ability is ... steel heat treatment or not heat treatment with state delivery, cold pull steel heat treatment with state delivery. 61SiCr7(1.7108) high quality spring steel ...