Dia: 30*30-800*800mm, Thickness: 3-40mm Material: Q235B, Q345B, 20#, ST37/44/52, ASTM A53/106,STKR490/400 Standard:GB/T 3094- Features:1) Dimentions: 30*30mm-800*800mm, Thickness: 3-40mm Length: <13m2) Material: Q235, Q345, 20#, ST37, ST44, ST52, ASTM A53, ASTM A106,STKR4903) Standards: JIS G 3466, DIN EN 10210, DIN EN10219, ASTM A500, GB/T 3094-2000, GB/T 6728-20024) Use: construction structure, ...