Hard anodising

Hard anodising is a special type of anodising.


During this process, it is possible to produce particularly hard, thick and friction solid layers, that meet industry standards in:

  • Wear
  • Friction
  • Electric field strength
  • Corrosion durability


Among other things, hard anodising is used for:

  • Cylinders
  • Gears
  • Bearings
  • Piston rods
  • Clutch discs

Structure and look after the treatment

  • The metallic impression is maintained.
  • The hard anodising layer is transparent, this means that the surface can be dyed black or have structure added.
  • Depending on the alloy, µm and temper, the surface can get a light brown or dark brown colour.
  • During a standard hard anodising the surface becomes rougher than after a traditional anodising. HAI Horsens can minimise the roughness of the surface.

Layer thickness

  • 30-150 µm depending on the alloy and the process.
  • At 50 µm a temper of 400-450 HV can be achieved depending on the alloy and the process.


  • Hard anodising can be dyed black.


  • Most alloys can be used.
  • The most well-suited alloys.

HAI hard anodises according to DS/EN 12373 and Mil-A-8625 Type III/ Class 1/ Class 2, as well as standards specific to clients. Certificates and reports of surface treatment tests from our own lab can be composed together with the client.


  • Al99/ 99,5
  • AlMn1 – AlMn1Mg0,5/1 – AlMnCu
  • AlMg1 – AlMg2,5 – AlMg3 – AlMg5
  • AlMgSi0,5/ 0,7/ 1
  • AlMg2Mn0,3/ 0,8
  • AlZnMgCu0,5/ 1,5

HAI’s specific hard anodising treatments:

  • Type 2000
  • Type 6000
  • Type 7000

Do you have questions?

You are always welcome to contact us on
+45 88 44 77 22