... 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 ... construction, sports venue, three-dimensional garage, exhibition hall.(4).Decoration: wrought iron doors and windows, outdoor advertising, ... need.Perfect after-sale service to solve your worries. High Quality Square steel pipe