The principal advantage of cold roll-forming, compared with other methods of fabrication, is the high production capacity achieved and is essentially uniform in cross section and can be manufactured to very close dimensional tolerances. Purlin, commonly termed as Z and C Sections, are defined by a central vertical web joined to horizontal flanges at either end. Additional lips are included to support the flanges. It is available in HR and GI grades and also in different thicknesses and depth depending on design of the building. Purlin can be supplied in customized length with pre-punched holes as per architectural designs.