... 60mm Certificate: ISO,API material:carbon steel API 5L carbon steel pipeline SpecificationsChina StandardSteel GradeStandardseamless steel tubesGB/T8162-199910, 20, ... 5LA, B, X42APIoil casing andtubing in oil wellsSeamles Steel TubesGB5310-199520G, 20MnG, 25MnG, 15MoG, 20MoG, ... 20ASTM A179, ASTM A192for low and Medium Pressure BoilersASTM SA179,SA192, BS3059Seamless Steel TubesGB6479-8610, 20G, Q345, ...