Square steel pipe OD: 30*30mm-800*800mm WT: 3-40mm Square steel pipeSpecification: 30-800mm thickness: 3-40mm material: Q235, Q345, 20#, ST44 ... , STKR490, ASTM A500 Standards:GB,DIN,JIS1) Dimentions: 30*30mm-800*800mm, Thickness: 3-40mm Length: <13m2) Material: Q235, Q345, 20#, ST37 ...