this kind of products is wildly used in building structure, power station tower and all other fields Features: 1) Material: Q195,Q215,Q235B,Q345,Q345B 2) finishing: black finished(or can be galvanized) 3)Spec:180x180x10-12mm,160x160x10-12mm,140x140x7-9mm,110x110x5-8mm, 90x90x5-8mm,63x63x5-6mm, 60x60x5-6mm, 56x56x4-5mm, 50 x 50 x 4-5mm,45x45x4-5mm, 40 x 40 x3-4mm, 30 x 30 x 3-4mm,25x25x3mm 4) ...