Ensures improved resistance to wear, even in aggressive environments, with treatment that works at several levels to deliver items with enhanced properties.

Benefits of hard anodising on aluminium

  • 01.

    Resistance to wear

    Hard anodised coatings are, on average, more than 10 times resistant to wear than normal anodised aluminium. Hard anodised aluminium demonstrates only half the amount of wear seen with cyanide hardening on steel after 50 cycles in a standard Taber abrasion test.

  • 02.

    Increased hardness

    Microhardness tests on anodised aluminium give values of 500 to 530 VPN.

  • 03.

    Improved roughness value

    Hard oxidation is also used to improve the roughness value and make an item impermeable to external agents.

  • 04.

    Uniformity even on unusual shapes

    Coatings follow the profile of the part with uniform distribution, implementing very strict tolerance control. It is also effective on unusually-shaped parts, thanks to excellent spot precision obtained in the hard anodising process.

  • 05.

    Resistance to heat

    Parts covered with hard anodising can resist brief exposure to temperatures up to 2000 degrees centigrade due to the inert nature of the coating.

  • 06.

    Resistance to corrosion

    Hard anodised coatings generally pass the 5% salt spray test for at least 336 hours (ASTM B-117). 

  • 07.

    Increased smoothness

    The hard oxide can make an item particularly smooth and is therefore suited to those areas where considerable anti-seize power is required.

  • 08.

    Excellent emissivity

    Hard anodised coatings demonstrate very low thermal expansion and conductivity properties, and excellent emissivity. At a larger thickness, emissivity is comparable to a black body in terms of heat dissipation.

  • 09.

    Excellent electric resistance

    Hard anodised coatings are excellent electrical insulators, exhibiting electric resistance to the same order of magnitude as glass and porcelain.


  1. Anodising thickness => from 20µ
  2. Anodising hardness => 400 HV
  3. Treatment carried out in compliance with standard MIL-PRF-8625F and QUALANOD specifications

Process of hard aluminium oxidation

The average thickness obtained with hard oxidation treatment is 20-60 micron. The treatment can be left in its natural grey colour, in shades that will depend on the initial alloy, or coloured black, making the entire aluminium item uniformly black.

The treatment can be impregnated with PTFE nano particles to lower the coefficient of friction and make the item smoother. Alticolor's systems can also offer hard colour oxidation, particularly suited to sectors working with items that need to combine resistance to atmospheric agents with aesthetics.

Since 1996, Alticolor has been the trusted point of reference for companies in need of treatments on aluminum components.

Alticolor treatments undergo rigorous control procedures
resulting in certification to guarantee the quality
of the process management.

  • certificato-uni-en
  • certificato-uni-cei
  • certificato-qualanod
  • certificato-en-9100-2018
  • certificato-nadcap


The service providing assembly operations in cleanrooms is available for anyone requiring products to be assembled in a controlled environment, and is available for every sector either as a final step following treatment or as a one-off service.

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Research and

Alticolor supports customers in the design phase through processes, analyses, research and prototypes that aim to create treatments that achieve maximum performance and aesthetics in the relevant sector of application.

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Different sectors, same care and quality.

Tell us about your project

We work closely with every company to identify the most suitable treatment to achieve the desired properties for your item. Tell us what you need and together we will find the best solution.

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