Box beam: This is a beam with a hollow, often rectangular, profile. It is known for being lighter than a solid beam of the same strength and for its high torsional (twisting) stability.

Materials: Box beams can be made from mild steel (sometimes called MS box span), or from two "C" shaped steel sections that are mechanically locked together. Applications: They are used in floors, roofs, decks, and bridges. For example, a "full span box girder" is a prefabricated bridge section that can be transported and installed in a single piece.

Span tables: Engineers use span tables, which provide detailed information on the correct product, size, and gauge of a box beam required for a given structural application