Steel Materials: steel materials comprises Q235A, Q235B, Q345A, Q345B, GR65, etc. coatings: hot-dipped shiny galvanization or dull grey galvanization, the thickness of zinc is more than 85um(microns) or be multi-color plastic spraying or powder coated after galvanization. welding: welding procedure has been certified by AWS(American Welding Society ) and our welders have got corresponding certificate after testing and inspection