... , 16...Thickness: 0.4 - 13 mmSection Shape: RoundOuter Diameter: 21.3 - 219 inchPlace of Origin: Tianjin China (Mainland)Secondary Or Not ... -frequency weldedZinc : 60-120g 200g 300g 400g/m2Outer diameter : 21.3-219mmWall thickness : 0.4-13mm Material: Q195,Q215,Q235,Q345 ... , GR.B, API J55, API K55, 10#,20#, etc.Length: 3-12m or as the customers' requirement.Standards: ASTM-A53, BS1378 ...