... Cold-rolling Seamless PipeStandardASTM, DIN, GB, BS, JIS, ASME, API, AISI,, ANSIGradeA333 GR3,GR6A335 P5,P9,P11,P12,P22,P91;A231 ... 10#, 16Mn, A106(B,C), 45#, API J55, API K55, St52, Q215, API N80, St37, API L80, API P110, St42, St45, St52.4API 5L A ... or According to customers' requirements.Surface Treatment3PE, 3PP,EP and Black PaintingApplicationFluid Pipe, Boiler Pipe, Drill Pipe, Hydraulic Pipe ...