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.

C purlin is primarily used to support walls and floors in steel building construction, often acting as beams for flooring and providing structural support for the building shell, including applications like door mounting, roof clipping, and window trimming; essentially, it's a C-shaped metal channel used to reinforce the structure of a building, particularly in smaller structures where heavy loads aren't required.