... design. ISO9001&ASTM Prefab steel structure workshop/Industrial building /warehouse construction Qingdao Baoduo Steel Structure CO.,LTD.Main Grade: Q345B, ... Garage,Hanger,Agricultral storage,Logistic centers,and all kinds of steel materials.,etc.Specifications:Main Steel: Q345B,Q235BColumn&Beam: ... with high strength bolts.4. The envelop construction net is made of cold form C-style purlins.5. Bracing ...