The thickness and high-quality of galvanized coating are crucial. The galvanized pipe ought to have a vibrant, easy surface with a good coating free of flakes and blisters.Tianjin square rectangular pipe / gi shs and rhs tube 20x20 25x25 40x40 50x50 60x60 20x40 30x50 40x60one.Barrier safety: The zinc layer acts for a Bodily barrier, avoiding h2o an