Sulfuric Acid Anodizing

Anodizing is a process that provides a conversion on aluminum which changes the surface of the material to a naturally occurring aluminum oxide. The oxide build up changes the surface of the aluminum which then provides greater abrasion resistance as well as increased corrosion protection (roughly 336 hours per ASTM B117). The finish will not only build up the aluminum oxide on the surface 0.0002″ – 0.0003″ thick, but will also penetrate into the material the same amount. Other than a clear anodize this coating may also be dyed in various colors. The typical industry colors include black, clear, green, gold, red, and blue. One other interesting property of the aluminum oxide is that it is a great electrical insulator.

MIL-A-8625 Type II

• Class 1: Specifies that there will be no dye applied to the finished part.
• Class 2: Specifies that there will be a dye applied to the finished part.

Base Materials that Anodize Type II can be applied include 1100, 2000, 3000, 5000, 6000, and 7000 series aluminum alloys.