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Type III Anodizing

Type III Anodized Aluminum Extrusion Bars

Gleco Plating offers Type III Anodizing for aluminum parts and products requiring increased surface hardness, thermal and dialectical properties, and wear/corrosion/abrasion resistance. Available in AMS 2468, AMS 2469, and Mil-A-8625, this finishing process increases the thickness of the naturally occurring oxide layer, giving it the name hard coating anodizing

Anodizing Process Options

The basic Type III Anodizing process involves:

  1. The aluminum part is connected to an anode.
  2. The part is submerged in an acidic electrolyte solution.
  3. A metal electrode is turned into a cathode. 
  4. An electric current of up to 100 volts is added to the solution. 
  5. The current is drawn across the anode to the cathode, depositing aluminum oxide onto the part.

Type III Anodizing can be employed in a nearly endless array of combinations of aluminum substrates, colors, and seals.

First, aluminum alloys that can be anodized include:

  • 1,000 series
  • 2,000 series
  • 3,000 series
  • 5,000 series
  • 6,000 series
  • 7,000 series
  • Sand-cast
  • Die-cast

Second, depending on the finishing process the anodized aluminum can be colored as:

  • Undyed or clear
  • Black
  • Blue
  • Red
  • Yellow/gold
  • Purple
  • Green
  • Brown

Finally, the anodized aluminum can be sealed using:

  • Hot deionized water
  • Nickel acetate
  • Impregnated Teflon
  • Sodium dichromate

Benefits of Type III Anodizing

Type III Anodizing is used as a finishing option for aluminum for its:

  • Wear resistance: More than ten times more wear-resistant than ordinary anodized aluminum
  • Hardness: Values of 500 to 530 VPN
  • Heat resistance: Can withstand short exposure to temperatures up to 2000 degrees centigrade
  • Corrosion resistance: Can pass the 1000-hour 5% salt-spray test
  • Lubricity: For slide applications

Typical Anodizing III Applications

Type III anodized aluminum is often selected for aerospace, automotive, food manufacturing, robotics, and industrial applications such as:

  • Valves 
  • Gears and pistons
  • Actuating cams
  • Hydraulic cylinders
  • Swivel joints
  • Sliding parts
  • Hinge mechanisms
  • Insulation plates

If you’re searching for a finish to keep your aluminum parts or products from corroding or wearing when exposed to the elements, contact Gleco Plating to discuss our Type III Anodizing services.