Rectangular tubes are formed from coils and then ran through a series of dies. They are welded from the inside to form their shape. Rectangular tubes are generally used for maintenance and structural purposes.

For mechanical and structural applications, rectangular hollow sections (RHS) are popular. This is because the flat surface makes it a more economical structural solution for joining and different types of manufacturing work. For soldering or joining, RHS requires minimal edge preparation. Because of the rectangular shape of this type of hollow section, parts only need to be cut straight when joining to other flat surfaces.