Square Steel Pipe : 1. More Thickness: 3.0-22.0mm 2. Advanced Roller Extrusion equipment line. 3.Certification:CE,ISO SpecificationsSquare Steel Pipe 1. More ... Q215, Q235, Q275, Q345, 20#, 45#, Stainless steel, Seamless steel, Alloy steel.3. SURFACE:Bared, Galvanized, Oiled, Color Paint, 3PE; Or Other Anti-corrosive ... Perfect after-sale service to solve your worries. High Quality Square steel pipe