... Roller Extrusion equipment line. 3.CE,ISO,ASTM A500,JIS ASTM A500 Galvanized Rectangular Steel Pipe 1. STANDARD:GB/ ... Stainless steel, Seamless steel, Alloy steel.3. SURFACE:Bared, Galvanized, Oiled, Color Paint, 3PE; Or Other Anti-corrosive Treatment ... Roads and Bridges: railway, aviation, expressway, overpass, road fence, traffic signs.(3).Construction engineering: steel structure construction, sports ...