Our Products Geometric Steels manufactures a complete range of C , Z , U , L , and Hat sections. Purlin and girts are available for a wide range of applications up to 3 mm thickness. Made from quality high-tensile galvanized CR & HR Steel. Geometric Steels Purlin and Girts can be supplied plain or punched. This is a fully integrated system, allowing for flexible design options. Geometric Steels purlins are manufactured from high tensile steel for increased strength, reduced weight, and a long service life.