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What is Anodizing?

One of the most common techniques for protecting the surface of metals, anodizing is an electrolytic process in which an oxide (anodic) layer is chemically built on the surface of the metal.

This oxide layer acts as an insulator and provides surface corrosion protection and serves as an excellent substrate for decorative finishes. In the case of anodizing aluminum the anodic oxide structure originates from the aluminum substrate itself and is composed entirely of aluminum oxide. It has a highly ordered, porous structure that allows for secondary processes such as coloring and sealing.

Anodizing is a “conversion coating” and is very different from paint, electroplating or other metal coatings. Anodize coatings are measured by thickness – the term thickness includes both penetration & build-up. While paints and plating sit on top of the surface of the aluminum, anodizing converts the outer layer of aluminum to aluminum oxide, so the coating is fully integrated with the aluminum substrate. This is the primary reason why anodize thickness is defined by the combination of the penetration into the substrate & the buildup of the oxide layer from the original dimension.
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Type I – Chromic Acid Anodizing
Type I – Chromic Acid Anodizing
Provides an oxide layer on aluminum for corrosion protection, electrical insulation, and improved dielectric strength
Type II & IIB – Sulfuric Acid Anodizing
Type II & IIB – Sulfuric Acid Anodizing
Improves surface corrosion protection under severe service conditions or as a base for paint systems. Type IIB – Thin Sulfuric Acid Anodizing serves as a non-chromate alternative to Type I and IB...
Type III – Hardcoat Anodizing (Hard Anodic Coatings)
Type III – Hardcoat Anodizing (Hard Anodic Coatings)
Provides wear and abrasion resistant surfaces with improved corrosion protection due to greater thickness and weight than the conventional anodic coatings
Magnesium Anodize
Magnesium Anodize
A unique finishing process utilized by some of the most highly specialized industries, Magnesium Anodize is an excellent surface finishing option for your magnesium components. Anodized magnesium...
Hip Joint Implant - Titanium Anodizing (1)
Titanium Anodize
Titanium Anodize
Type II Titanium Anodizing is used as an anti-galling coating without additional lubrication or as a pretreatment for improving adherence of film lubricants and in application where increased...
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Benefits of Metal Finishing

Although metal finishing is a simple idea, it is one that can accomplish many goals, including >>


From its humble beginnings with our ancestors to the advanced techniques we employ today, metal finishing is part of our unending collective effort to improve the performance of the tools we build and the beauty of the things we create.

  • Preventing Corrosion
  • changing conductibility
  • altering emissivity
  • enhancing or reducing conductivity
  • modifying lubricity
  • improving wear
  • increasing hardness
  • improving heat response & resistance
  • enhancing aesthetic appearance
  • Preventing Corrosion

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