... Q275, Q345, 20#, 45#, Stainless steel, Seamless steel, Alloy steel.3. SURFACE:Bared, Galvanized, Oiled, Color ... Paint, 3PE; Or Other Anti-corrosive Treatment.4. TECHINQUE:Hot rolled, Cold rolled, ERW, High ... fence, traffic signs.(3).Construction engineering: steel structure construction, sports venue, three-dimensional ... . High Quality Square steel pipe