Type III,
Hardcoat Anodizing (HCA)

The primary objective of this process is to obtain a hard coating, resistant to abrasion. It is obtained using an electrolyte of sulfuric acid at low temperature with high voltage and curent density.

Chromic Acid Anodizing

This anodizing offers the highest wear resistance.
It provides good electrical insulation (800V/mil) and is thicker and denser than sulfuric anodizing. The films range from .002"-.004" thick. (50% penetration, 50% over substrate). The dimensions of this process will change and have to be considered into the design. It is compatible with the alloys from 5000 to 7000 (please call for special applications). The hardness of the anodic layer ranges from 60 to 70 Rc and it's natural color varies from charcoal to dark bronze depending on the alloy (May be colored to black only).

This process is recommended for aluminum components subject to extreme wear or corrosive environments. It can be used to reconstruct a surface worn or miss-machined part to size.

Please note that Hardcoat Anodizing is more expensive than other types.


Improved wear resistance : The coating is harder than tool steel.
As with other types of anodizing, it is non-conductive. The only custom appliable color is black, but it can be buffed, polished or honed.
Can be used to rebuild a worn or miss-machined surface of a part to the desired dimension


Perfect for valves, pistons, sliding parts, rails, bushing, as well as tooling, hinge mechanisms, gears, cams, swivel joint or insulation plates.

Sulfuric Acid

Type I, Chromic Acid Anodizing (CAA)

First commercial type of anodizing, widely used in aerospace and defense. It minimises metal fatigue and is compatible with many aluminum alloys.

Sulfuric Acid

Type II, Sulfuric Acid Anodizing (SAA)

Most frequently used type of anodizing, this process will generate a decorative or protective surfaces with a greater durability than surfaces treated with type I. Sulfuric anodize provides a minimum 336 hours of 5% salt spray resistance per ASTM B117.

Boric Sulfuric

BAC 5632 / MIL-A-8625 Boric Sulfuric Anodizing

Developed by Boeing Aerospace as a chrome free alternative to type I, for non-critical fatigue part. The adhesion to paint is equal or superior to Type I and this type of anodizing provides corrosion protection.