The square pipe is a hollow square section steel tube with a square cross-sectional shape and a shape obtained by hot-rolled or cold-rolled galvanized steel strip or galvanized coil as a blank after cold bending forming and then high-frequency welding. Square tube form their shape from internal welds. Galvanized square tubing protective effect is stronger and its corrosion resistance is strong,mainly used in solar panel tilting brackets, steel construction projects,shipbuilding, etc.