spring steel flat bar 60Si2Mn 42CrMo Gcr15 50CrV4 51CrV4 65Si7 SUP7 Sup9 Sup10 SAE5160H 50CrV4 SAE6150H We are making the spring flat steel bar all the time ,the detail information is as flw :1,Grade: GB: 65Mn ,55Si2Mn , 60Si2Mn ,55CrMnA ,60CrMnA ,50CrVA, 60CrMnBA,55SiMnVBA , 60Si2CrA JIS : SUP7,SUP9,SUP9A,SUP10,SUP11,SUP12 ASTM: 1566 ,9255,9260,5155,5160,6150,51B6,9254 DIN: 55Si7 ,60Si7, 55Cr3, ...