Is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts.

• Sulfuric Anodize Per: MIL-A-8625 Type II
  

The coating serves as a corrosion inhibitor, as a primer to improve the adherence of paints and adhesives, as a decorative finish, or to preserve electrical conductivity. It also provides some resistance to abrasion and light chemical attack (e. g. from dirty fingers) on soft metals.

• Chemical Film Per: MIL-C-5541/MIL-DTL-5541

The coating serves as a corrosion inhibitor, as a primer to improve the adherence of paints and adhesives, as a decorative finish, or to preserve electrical conductivity. It also provides some resistance to abrasion and light chemical attack (e. g. from dirty fingers) on soft metals.

• Zinc Per: ASTM B 633 Types I, II, & III (Clear, Gold, & Black)

Refers to coating a material so it becomes "passive," that is, less readily affected or corroded by the environment. Passivation involves creation of an outer layer of shield material that is applied as a micro-coating, created by chemical reaction with the base material, or allowed to build by spontaneous oxidation in the air. As a technique, passivation is the use of a light coat of a protective material, such as metal oxide, to create a shield against corrosion