Carbon seamless steel tube steel grade: 10#, 20G, 12CrMo, 15CrMo; Standard: GB9948 Carbon Seamless Steel Tube for Petroleum CrackingSteel grade: 10#, 20G, 12CrMo, 15CrMo;Standard: GB9948;Specification : OD: 10mm-114.3mm (0.4055"-4.5"), WT: 2mm-22mm (0.0787"-0.8661"); Dimension tolerance: O.D.: +/-0.08mm, W.T.: +/-10%. Carbon Seamless Steel Tube for Petroleum Cracking