... Economical structure,Modern Looking. ISO9001&ASTM steel roof truss/Industrial building / prefabricated factory Qingdao Baoduo Steel Structure CO.,LTD.Main ... EnterpriseCertificate:AWS Welder Passport From USA We are a Factory-direct provider of all kinds of steel structure ... : Q345B,Q235BColumn&Beam: Welded or Hot rolled H-sectionWall&Roof: EPS, Rockwall, PU sandwich ,corrugated steel sheetDoor: Rolled ...