... 15--300MM We are making the spring steel flat bar , spring round bar all the time ,the detail information is as flw :1, ... : 55Si7 ,60Si7, 55Cr3, 58CrMnB42, SIZE: flat bar : thick: 5-90 mm width : 40-250mm round bar: 5.5 - 3003, payment : BY 30 ...