This standard specifies requirements for hard anodic oxidation coatings for aluminium and its alloys, including test methods and technical specifications for coatings. Coatings formed by hard anodic oxidation are used to enhance the abrasion resistance, electrical insulation and corrosion resistance of aluminium alloys. Coating thicknesses range from 25 μm to 150 μm, and the thickness is selected according to the needs of the specific application. The standard also specifies treatment requirements before anodic oxidation and dimensional changes of coatings to ensure the effectiveness of coatings in various engineering applications.