To enhance the durability of Japanese standard steel profiles, several surface treatments are commonly employed. Hot - dip galvanizing is a prevalent method. By immersing the profiles in molten zinc, a thick and adherent zinc layer is formed, which acts as a sacrificial barrier, protecting the steel from corrosion. Galvanized profiles are suitable for outdoor applications and can last for decades in normal environments. Painting involves applying anti - rust primers followed by protective topcoats, such as epoxy or acrylic paints. This treatment not only provides corrosion protection but also allows for aesthetic customization, making it suitable for both indoor and outdoor structures. Zinc - rich coating is another option, especially for high - performance requirements. The zinc - rich primer contains a high proportion of zinc powder, which offers superior cathodic protection. For weathering steel profiles, no additional protective coating is usually required as they form a stable, adherent rust layer over time, which protects the underlying steel from further corrosion in outdoor atmospheres.