... 2. Advanced Roller Extrusion equipment line. 3.CE,ISO,ASTM A500,JIS ASTM A500 Galvanized Rectangular Steel Pipe 1. STANDARD:GB/T3094-2000, GB/T6728-2002 ... 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 ...