SCH40 steel pipe OD:7.8mm-289.85mm material:20 #, 35 #, # 45,27 ... pressure boiler pipe GB3087-1999, high-pressure boiler pipe GB5310-1995, oil cracking pipe, GB9948-88,, shipsseamless pipe GB5312-1999, hydraulic prop pipe GB/T14976 ... , T91, P91, T9, Cr5Mo (PS \ STFA25), 10CrMo910 (P22), 15CrMoG (P11 P12, STFA22), WB36 ,12-42CrMo, 20CrNIMo, 25Cr2MoV, 27SIMo ,25-40CrMnMo, 35Mo2VNb ...