square hollow section:Original, high-quality, fast delivery, good follow-up service, relevant technical consultation Description: Steel square tube/rectangular pipe/rectangular tube/stainless steel square tube/square tube/ square pipe/ welded square tubeMaterial: ASTM/GB/JIS/BS Hot Rolled Square PipesSteel gradeQ195, Q215, Q235, Q345,ST37,ST52Outside Diament15*15-600*600mmThickness0.5-40mmLength5 ...