Welded square and rectangular tubes, also known as welded hollow sections (WHS), are essential structural materials widely used in construction, mechanical manufacturing, automotive engineering, furniture production, and industrial frameworks. These tubes are formed by rolling and welding steel strips or coils into square or rectangular shapes, offering excellent strength, dimensional precision, and cost efficiency. Compared with seamless tubes, welded tubes provide greater flexibility in size customization, lighter weight, and more economical production — making them a preferred choice for structural and decorative applications worldwide.