BAC 5632 / MIL-A-8625
Boric Sulfuric Anodizing

Developed by Boeing Aerospace as a chrome free alternative to Chromic acid anodizing for non-critical fatigue part, this process type offers superior paint adhesion and corrosion protection

Chromic Acid Anodizing

Environmental friendly alternative to chromic anodizing, this type of process is used for corrosion protection and paint adhesion. It is applicable to aircraft and aerospace components MIL-A-8625, Type Ic and Boeing's BAC 5632


Good for tight tolerance parts as it will not change dimensions. Boric Sulfuric Anodizing provides corrosion protection and paint adhesion, has good bonding properties and is also non-conductive.


This process type is used for precision machined components as well as for aircraft and aerospace components.

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.


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 current density.