... 2)HDG with powder coating 3)5m-15m are available 4)Octagonal, round 5)Lower cost The Single arm solar panel ... through bending, forming, automatic welding, hot dip galvanization and powder coating. We owned advanced production-line, it included Flatting machine, ... Auto-closed up machine, submerged arc welding machine and powder coating line, and our workmanship and quality control was achieved high ...