Anodizing

Anodizing involves an acid bath and electricity which, when used together, is a controlled oxidization that enhances the naturally occurring oxide layer on aluminum. It is this controlled oxidization that makes the oxide surface thicker and therefore, harder.

The aluminum is secured to racks and then lowered into an acid bath. An electric current is then passed through the racking and into the aluminum part. The anodized aluminum can be left in its natural color, or dyed from many color choices, using organic dyes.

Also known as common or standard anodizing, Type II is sulfuric acid anodizing (as opposed to Type I anodizing, which is chromic acid anodizing).

Type II anodizing includes two different classes:

• Class I signifies an un-dyed finish, also called clear or natural

• Class II signifies a dyed finish and the color is named ( i.e.: Type II Class II Red)

Type III anodizing is also sulfuric acid anodizing.

The key difference between Type II and Type III is that for Type III anodizing, the sulfuric acid solution's temperature is lowered and run at a higher voltage.

The end result is a denser, wear-resistant oxide layer that creates a harder and smoother finish than Type II anodizing. Type III anodizing is ideal for parts that rub together.

Our standard methods can process components of aluminum with the following maximum dimensions, based on the type of anodizing you are requesting:

It is important to note that there will be a difference in color between your aluminum part and where it has been welded.

This is because when aluminum parts are welded, they undergo a thermal process that alters the metal's microstructure. This change in the aluminum's microstructure affects the color of the anodized layer.

The areas where a part has been welded, as well as the periphery, will not be a uniform color compared to the other areas of the part.

Our anodizing suppliers cannot guarantee color uniformity, especially for larger parts or parts in larger unit quantities. For consistency in anodizing color, we recommend small-sized parts in small volumes. Some parts may have racking marks.

There are many advantages to choosing an anodized finish for your enclosure, part or component: