... 5CT API 5L/ASTM A53/A106EN10255GB/T9711.1A25,A,B,X42,X46,X52,X56,X60,X65,X70S235J2H,S355J2H10#,20#,Q295,Q345,GrAGrB,GrC,Q235B,Q345B,SS4000 ... 6.4mm-38.4mmTubes for Structural Purposes & Ordinary PipeSquare steel tubeGB/T 3091GB/T 6728JIS G 3444ASTM A513ASTM A500BS 1387EN ... GR.CSt37,st52S235J2H,S355J2H20*20-400*400mmX 1.0mm-16mmRectangular steel tube30*20-500*300mmX 1.0mm-16mmRound pipe1/2inch-60inchX ...