Hard Anodizing

Hard Anodizing, often called “Type III Anodizing” as denoted by the MIL-A-8625 specification, is an electro-chemical process that creates a controlled oxide film on the surface of aluminum. Hard Anodizing utilizes sulfuric acid, low bath temperatures, and constant current rectification to achieve a very hard coating (60-70 Rockwell C). Hard Anodizing is generally used for applications that need a corrosion, abrasion, or wear resistant coating.

The appearance of the coating ranges from light to dark gray, depending on the alloy makeup of the aluminum base material, and it can also be dyed particular colors. Parts can be processed with multiple finishes, such as Hard Anodize/ChemFilm or Hard Anodize/Electroless Nickel Plating.