B.I. and G.I.
C-Purlin

Purlins, also known as “sheeting rails”, are commonly used for structural support of roofs. Aside from that, it can also be used in walls, rafters, floor joists, and studs for walls. It comes in two shapes, distinguished by their names: C-Purlins and Z-Purlins.

It is available in 2 variants – black iron (B.I.) and galvanized iron (G.I.). Galvanized Iron is covered with zinc to make steel resistant to rust. Black Iron is uncoated and the black color is from the iron oxide made on its surface throughout the manufacturing process.