Hard anodizing, also known as hard coating anodizing or type III anodizing.

The principle of hard anodizing of pure sulfuric acid type aluminum alloy is not fundamentally different from ordinary anodizing. The main purpose of hard anodizing of aluminum parts is to improve various properties of aluminum and aluminum alloys. Such as corrosion resistance, wear resistance, weather resistance, insulation, and adsorption. Anodizing type III is not only suitable for deformed aluminum alloys, but also for die-casting aluminum alloy parts.

The thickness of the general hard anodized film is between 13-150 μ m.

For hard anodized films with a thickness less than 25 μ m, they will be used for the key teeth and spiral parts. The thickness of the anodized film for wear resistance or insulation is about 50 μ m. Under certain special process conditions, it is necessary to produce a hard anodized film with a thickness of 125 μ m or more. However, it must be noted that the thicker the anodic oxide film, the lower the microhardness of the outer layer, and the roughness of the film surface will also increase.

Usually, the standard thickness of our aluminum alloy hard anodized film is 25-50 μ m.

Hard anodizing processing

Matte black hard anodized, sandblasted