... .12CrMoV,15CrMo,30CrMo,St37-52 2.OD:5-630mm 3.WT:0.5-120mm seamless black steel pipe1.Material: ASTM A53 ... /A106, GB8162, 12CrMoV,15CrMo,30CrMo,St37-522.OD:5-630mm3.WT:0.5-120mm4.Application: making Mechanical Parts, pipe fittingswe professionally ...