A square hollow section (SHS) tube, also known as cold-drawn steel aluminum profile, is a lightweight, thick-walled, seamless steel tube with a square cross-section. It is produced by cold bending and forming steel strips or plates, typically of Q235 grade, into a square shape after being processed through a high-frequency welding machine. The hot-rolled extra-thick-walled SHS tube not only has increased wall thickness but also features corner specifications and edge perpendicularity that exceed those of cold-formed resistance-welded SHS tubes. It boasts excellent comprehensive physical properties, good weldability for large-diameter square rectangular tubes, favorable heat treatment characteristics, and corrosion resistance. Additionally, it exhibits excellent ultra-low-temperature ductility.