Type III Hardcoat Anodize


Type III Anodizing , also known as Hardcoat Anodizing or Hard Anodizing, is similar to Type II Anodizing, but creates a thicker, more durable layer of aluminum oxide on the surface of the finished part. This is accomplished by manipulating the current density and bath parameters. After this process, the resulting finish has superior wear and corrosion resistance. As with Type II Anodizing, the finish is integral to the part as it penetrates the part as well as builds up on the surface.


  • High corrosion resistance
  • High durability
  • Electrical insulation
  • Buildup of worn surfaces on aluminum
  • Improved color and appearance. Hardcoat anodize coatings may be dyed, as with Type II. The resulting colors are not as vibrant.
  • Extreme wear resistance
  • Hard durable surface

Typical Industries and Applications:

  • Machinery, for its wear resistance especially with high-speed machine parts
  • Electronics, provides constant emissivity
  • Marine, for its corrosion resistance, especially with salt-water
  • Oil, for its excellent corrosion and wear resistance
  • Air and Space, for durability, longevity, and light weight
  • Cookware, for corrosion protection and non-stick properties
  • Automotive
  • Firearms
  • Recreational
  • Sporting Goods

Common Specifications:

  • MIL-A-8625 TYPE III

Common Substrates:

  • 6000 series
  • 5000 series
  • 7000 series

Coating Thickness vs. Corner Radius

Nominal Coating Thicknessā€¦inch Radius on edge & inside corner
0.001 ~ 1/32 inch
0.002 ~ 1/16 inch
0.003 ~ 3/32 inch
0.004 ~ 1/8 inch

Anodize Diagram