... DIN17175,GB30872)Oil pipe:GB99483)High-pressure seamless tube:GB64794)Hydraulic pillar tube:GB/T173965)Shipping pipe:GB/T53126) ... pipe:20,12CrMo,15CrMo3)High-pressure seamless tube:20,16Mn,Q3454)Hydraulic pillar tube:27SiMn5)Shipping pipe:4106)Pipe ... Co., Ltd. Major steel production of seamless steel pipe, straight seam steel pipe, spiral steel pipe, galvanized steel pipe, steel sheet, strip, valves ...