Hardcoat anodizing and why it’s important.

Anodizing TankHard coat anodizing is a finish that provides a durable surface that prolongs the life of an aluminum surface. When done properly the life of the product is increased as long as the proper care is taken.

Hardcoat Anodize is a dense anodic coating of aluminum oxide applied by converting a properly cleaned and deoxidized aluminum alloy component into an oxide film using an electrolyte, typically sulfuric acid cooled to nearly freezing, and applying voltage upwards of 100 volts at an applied current density of 24-36 amps per square foot.


Hard Anodize Features:

  • Increased abrasion resistance
  • Increased wear resistance
  • Increased corrosion resistance
  • Improved aesthetics
  • Improved lubrication (particularly when PTFE sealed)
  • Readily sterilized, non-contaminating.
  • Improved wear resistance
  • Non-conductive
  • Can repair worn surfaces on aluminum
  • Improve parts surface for slide applications
  • Can be black dyed; other colors less decorative
  • Finish is harder than tool steel

What industries benefit from doing Hardcoat Anodize?

  • Aerospace
  • Automation / Robotics
  • Electrical
  • General Manufacturing
  • Machine Tools
  • Medical
  • Military / Defense
  • Fire Departments
  • Water Departments

Non dyed, is Class 1, Hardcoat anodizing will change the color of the aluminum depending on the particular alloy and the anodic thickness. The color of the aluminum after being Hardcoat anodized depends on the alloy and the thickness of the coating. Many of the 6-series of aluminum will take on a deep gray-black color while most 7 and 2 series will appear a more bronze or gray color.  On some alloys, the color of the aluminum after Hardcoat anodizing will be gray and bronze. For a dyed Class 2 coating, black is the most commonly specification and will take on a very uniform appearance. Due to the dark nature of the undyed coating itself, other colors are not as decorative or uniform appearing.