1 category:square tube 2 grade:Q195-Q235-Q235B-Q345-Q345B 3 certification:ISO9000: ... :20007)Application:Widely used in water supply, construction support, mechanical tube, etc.8)Export: Europe, North America, the Middle East, Africa ... tube, galvanized square tube processing, hot dip galvanized rectangular tubes, square tubes of large diameter, export processing hit boxes, etc. of the integrated ...