spring round bar steel 15--300MM We are making the spring steel flat bar , spring round bar all the time ,the detail information is as flw :1,Grade: GB: 65Mn ,55Si2Mn , 60Si2Mn ,55CrMnA ,60CrMnA ,50CrVA, 60CrMnBA,55SiMnVBA , 60Si2CrAJIS : SUP7,SUP9,SUP9A,SUP10,SUP11,SUP12ASTM: 1566 ,9255,9260,5155,5160,6150,51B6,9254DIN: 55Si7 ,60Si7, 55Cr3, 58CrMnB42, SIZE: flat bar : thick: 5-90 mm width : 40- ...