Galvanized square tube is divided into hot-dip galvanized square tube and cold-dip galvanized square tube from the production process. This square tube is based on a square tube formed by placing the square tube in a hot-dip galvanizing bath after a series of chemical reactions. The cold-galvanized square tube uses the principle of cold-galvanizing on the square tube used to make the square tube anti-corrosion.

Galvanized pipe, also known as galvanized steel pipe, is divided into hot-dip galvanized and electro-galvanized. The hot-dip galvanized layer is thick, the coating is uniform, the adhesion is strong, and the service life is long. The cost of electroplating is low, the surface is not smooth, and the corrosion resistance is worse than that of hot-dip galvanized pipe. Galvanized pipes include galvanized round pipes, galvanized square pipes, galvanized seamless pipes, galvanized welded pipes, etc.

Ordinary galvanized steel pipes are seamed steel pipes. Galvanized steel pipes are only available on special request. The way to distinguish between seamed and seamless steel pipes is to measure the outer diameter of the pipe. The manufacturing standards of the two steel pipes are different, and the outer diameters are also different. For example, for a steel pipe with a diameter of 100mm, the outer diameter of the seamed one is 114mm, and that of the seamless one is 108mm.

There are two types of galvanized square tubes: hot-dip galvanized square tubes and electro-galvanized square tubes. There are wet method, dry method, lead-zinc method, redox method and so on for hot-dip galvanized square tube. The main difference between different hot-dip galvanizing methods is the method used to activate the surface of the pipe body to improve the quality of galvanizing after the steel pipe is pickled and cleaned. Dry method and oxidation-reduction method are mainly used in the current production, and their characteristics are shown in the table. The surface of the electro-galvanized zinc layer is very smooth and dense, with a uniform structure; it has good mechanical properties and corrosion resistance; the zinc consumption is 60% to 75% lower than that of hot-dip galvanizing. Electro-galvanizing is technically complicated, but it must be used for single-sided coating, double-sided coating with different thicknesses on the inner and outer surfaces, and thin-walled pipe galvanizing.