C purlins, also known as Cee purlins, are in the shape of the letter C and provide structural support for beams required for walls and flooring. In addition to roofing, C purlins are often used for structural support in walls and as floor joists.

Channel steel is a long strip of steel with a groove-shaped cross-section. It is a carbon structural steel used in construction and machinery. It is a profile steel with a complex cross-section and has a groove-shaped cross-section. Channel steel is mainly used in building structures, curtain wall engineering, mechanical equipment and vehicle manufacturing.