Our company is specialized in producing ERW Steel Tube. The product are used for steel structure construction,coal mine,machinery,ship-building and household and are populai among customers. Product specification: Square steel pipe: Size: From 40x40mm to 400x400m, Thickness: from 2.5mm to 14mm Rectangle steel pipe: Size: From 60x40mm to 500x300mm, Thickness: from 2. 5 to 14mm Steel grade: Q195, Q235, Q345, 16Mn (SJ255, St37)