Square tubes are a type of hollow, square cross-section lightweight thick-walled seamless steel tubes, also known as cold drawn steel aluminum profiles. They are produced by cold bending and forming from Q235 hot-rolled or cold-rolled steel strips or coils, then焊接 into the square cross-section shape by a high-frequency welding machine. The hot-rolled thick-walled square tubes, in addition to having thicker walls, also meet or exceed the specifications of the corners and verticality of the edges compared to cold-formed square tubes from resistance welding machines. They offer excellent comprehensive physical properties, good electric welding performance for large-diameter square rectangular tubes, excellent heat treatment characteristics, and corrosion resistance. They also possess superior ultra-low temperature ductility.