Hardcoat Anodize

Hard Anodize (TYPE III) or Hardcoat”  is a highly abrasion resistant/non-conductive coating that makes an aluminum surface harder than tool steel due to greater thickness & weight than conventional TYPE II sulfuric anodize. Hardcoat is specified for aluminum components subject to extreme wear, applications where superior abrasion resistance is needed, and/or for corrosive environments where a thicker, harder, more durable coating is necessary. Hardcoat can also be valuable where enhanced electrical insulation is required.

Hardcoat Features & Uses
  1. Improved wear resistance
  2. Improved surface for slide applications
  3. Can be ground or lapped
  4. Finish is harder than tool steel
  5. Non-conductive
  6. Can repair worn surfaces on aluminum

Since hardcoat can potentially be built up to several thousandths, this process can be useful for salvaging worn or mis-machined components

  • Actuating Cams & Hydraulic Cylinders
  • Sliding Parts & Hinge Mechanisms
  • Valves, Pistons & Swivel Joints
  • Insulation Plates & Blast Shields
  • Gears, Wear surfaces – and more!



At Aotco, we plate to your specified coating requirements.

If coating is not specified on contract or applicable blue prints, the nominal Hardcoat thickness shall be .002
**Hard Anodize Thickness = ~ 50% Penetration & ~ 50% Build-up**

Please visit our “Anodize Coating” page for information about Hard Anodize & thickness

 Type III coating thickness can range from a several tenths to few thousandths, depending on the alloy.
Where Maximum serviceability/special properties are required, consult metal finisher for best alloy choice.