A square steel pipe is a type of hollow, rectangular steel tubing that is characterized by its square cross-section. It is made from steel strips or plates that are bent and then welded together to form a square-shaped tube.

Square steel pipes are commonly used in construction, infrastructure, and mechanical engineering applications. They can be used as structural supports in buildings, as handrails and guardrails, in fencing and gates, and in the production of various mechanical components. Square steel pipes are often preferred over other types of steel pipes because of their strength and durability, as well as their clean and modern appearance.

Square steel pipes come in a variety of sizes, thicknesses, and finishes, and can be made from a range of steel grades to suit specific project requirements. They can be galvanized or coated with other protective materials to enhance their resistance to corrosion and weathering.