Commodity:Hot Rolled Square Tube(Square steel pipe,steel tube). Material:Q235B/Q345B and so on. Commodity:Hot Rolled Square Tube(Square steel pipe,steel tube).Material:Q235B/Q345B 20#,10#,35# ,16Mn, 27SiMn, 40Cr, 12CrMo, 15CrMo, 35CrMo and 42CrMo. Steel Hollow Section, Hot rolled Square tube