... the main power system, the machinery industry, the pharmaceutical industry, pharmaceutical plants and steel boiler steel. System metallurgical ... machinery, high-rise buildings, civil span. Structural steel tower masts and other friction-link project. I bolt steel companies choosing the material ... GB/T 1228-1231,ASTM A325 A490 A325M A490M1- Raw material : 40Cr,35Crmo2-Surface hardness: HRC:34-38,38- ...