... Extrusion equipment line. 3.Certification:CE,ISO SpecificationsSquare Steel Pipe 1. More Thickness: 1.0-22.0mm ... Q215, Q235, Q275, Q345, 20#, 45#, Stainless steel, Seamless steel, Alloy steel.3. SURFACE:Bared, Galvanized, Oiled, Color Paint, 3PE ... ).Construction engineering: steel structure construction, sports venue, three-dimensional garage, exhibition hall.(4).Decoration: wrought iron doors and ...