... #, # 45,27 SiMn, 16Mn (Q345B CDE), 20G, 12Cr1MoVG, SCH40 steel pipetypeSCH40 steel pipeOD7.8mm-289.85mmWT2.35mm-37.8mmstandard structural tube GB ... , oil cracking pipe, GB9948-88,, shipsseamless pipe GB5312-1999, hydraulic prop pipe GB/T14976-1998,material20 #, 35 #, # 45,27 SiMn, 16Mn ...