Steel frames are made of steel that is protected against corrosion by a hot-dipped metallic coating of either zinc/aluminium alloy or zinc (galvanized).

The metallic coatings conform to the appropriate Australian standards or their equivalent. In applications such as roofing, these products are exposed to the elements and have excellent durability, so naturally in less exposed applications such as inside the building envelope they give even longer service. Where there are drill holes and cut edges the galvanic actions of the coatings protects the exposed steel edge against corrosion.