Chromic acid anodising

Chromic acid anodising is an alternative to sulfuric acid anodising, which is used when a coating with great corrosion durability and good adhesiveness is desired.


  • Particularly well-suited for aluminum subjects with lots of cavities, studs and the like, as chromic acid residue does not attack the metal like sulfuric acid does.
  • Very well-suited as pre-treatment for bonding and finishing, because of the good adhesiveness and corrosion durability.


  • Aviation
  • Military

Structure and look after the treatment

  • The metallic impression is maintained.
  • The anodising layer is transparent.
  • The colour turns light grey.

Layer thickness

  • 2-5 µm
  • The coating appears in different grey shades depending on the alloy.


  • Can be dyed in different dark colours.
  • The coating is sealed in hot water, if it needs further surface treatment.


  • Most alloys can be used.
  • Cast alloys should not be used.
  • Alloys containing more than 5 % copper should not be used.
  • As pre-treatment for finish and bonding the coating should not be sealed

Do you have questions?

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