... GS ASME DIN GB Rectangular hollow section pipe 1.Technique: ERW, hot rolled, cold rolled, cold drawn, extrusion.2.Standard: ASME,ASTM ... ,Q215,Q235,SS440,20#,45#,Q345,16mn,Q390,ST52TechniqueERW,extrusion, hot rolled, cold rolled, cold drawnSurface TreatmentPainting, Coating, Galvanizing,PackagePipe cap ...