... ,DIN,BS,JIS,BS,GOST materialAPI J55/N80/P110,10#,20#,50#,A53A,A53B,Q345,etc length4M-14M,R1,R2,R3 ... pipe diameter:16mm-610mm, thickness:0.3-20.0mm2. Square tube:16*16mm-400*400mm,thickness:0.8-20.0mm3. Rectangle tube:19*10mm ... -500*300mm,thickness:0.8-20.0mmIV. Surface finish: black, blank ...