Iridite NCP over Alocrom

Choosing Iridite NCP over Alocrom 1200

For many years, the process for coating aluminium parts and components involved a rapid dip technique, using Alocrom 1200. This coating was cost-effective and could be performed at volume, and provided a protective chromate coating for aluminium substrates and aluminium alloys.

Recent changes in environmental legislation has lead to Alocrom 1200 being made illegal for aluminium coating purposes (as well as a number of other applications) except under special license. The reason is that Alocrom contains hexavalent chromium, which is a proven carcinogen and has been linked to an increased risk of lung and respiratory cancers.

Fortunately for our customers across the UK, there is a safe and effective solution to your aluminium coating need – iridite NCP.

What Is Iridite NCP?

Iridite NCP (or non-chromium passivate) offers all the advantages of Alocrom 1200, without the health, safety, and environmental concerns associated with it. The substrate needs to be carefully cleaned of all impurities and contaminates for the iridite to form an effective bond. At Karas Plating, we perform this cleaning process in-house to ensure the quality of the coating.

Once cleaned, the substrate is lowered into an acid bath, starting a chemical reaction that creates a thin coating across the surface of the metal. This coating boasts several important qualities that make it a popular choice across many industries.

These are just a few of the ways Iridite NCP can benefit your company…

Corrosion Resistance

Iridite NCP is extremely resistant to corrosion, making it a useful in harsh environments (including beneath the ocean in the petrochemical industry). It has been tested on many aluminium alloys and shown to withstand corrosion for up to 1000 hours.


Iridite NCP can also be used on equipment with high operating temperatures, thanks to its heat-resistant qualities. This makes it much sought after for electronic heat sinks, automotive engine components, and more.


Applying iridite NCP requires careful preparation that can extend the process time. However, unlike many chromate treatments (including Alocrom 1200), iridite NCP does not require a long drying time. Instead, the coating dries as it is formed on the substrate.


Among its many qualities, iridite NCP provides excellent adhesion to paints, primers, and sealants. This makes it a good choice in the automotive, aeronautical, and defence industry.

Get in touch

For more information on our iridite NCP passivation process and how it can help you, contact Karas Plating today. Call us on 0333 121 0151 for a free, no-obligation quote.