According to the actual needs of the use of products for further processing, such as cold galvanized square tube, hot galvanized square tube, can improve the corrosion resistance, rust and other problems. Outdoor use, hot plating is relatively not easy to rust, cold plating is generally used for indoor use. Fangtong is mainly used for welding shelves, curtain walls, decoration, machining, steel structure, daily necessities components, etc. As a member of pipe, it is widely used.