square hollow section of best quality: Material: Q195, Q215, Q235, Q345B, X42, Gr. B square hollow section of best quality:hollow section, good quallity and ... BS, JIS, 3.Material: Q195, Q215, Q235, Q345B, X42, Gr. B4.Specification: OD: 15*15mm-400*400mm, WT: 0.6mm-12mm 1 ... MaterialQ195---Q2354. Size a. side length15mm--600mm b. W.T.0.3mm--13.5mm5. LengthMax 13 meters6. StandardGB/T6728-2002 or ...