... .8-9mm 4.Length:5.8-12m Basic Information:Square tube is the tube that have equal side length. The steel strip welded ... round tube and then rolled into the square tube. StandedAISI, ASTM, BS, DIN, GB, JIS, etcGradeMild ... kind of pipes, Galvanized Steel Pipe, Seamless Steel Pipe, Square/Rectangular Steel Tube, Light/Heavy Steel Rail and ect. It is our goal ...