There’s more than one way to anodise metals. All of these create a protective layer and even-looking finish to parts and surfaces, but each offers different specific benefits. We take a look at three of the most well-known types of anodising.

Sulphuric Acid Anodising

This is a very common form of chemical anodising that uses a sulphuric acid solution. It results in a medium-thick layer of coating, making it ideal for colour-based finishes, as the thicker layer can hold the colour. It is commonly used in the automotive industry as it offers a high level of protection combined with an aesthetic finish.

Chromic Acid Anodising

This is a less common choice and produces a much thinner layer than other methods, making it less suitable for coloured finishes. However, it is well suited to precision components that cannot afford to lose fatigue strength, such as aerospace parts. This method is being phased out and replaced by the more eco-friendly tartaric sulphuric acid anodising method.

Hard Anodising

Hard anodising, as the name suggests, produces the toughest layer of all three. It is therefore used in heavy machinery, including moving parts such as gears, offering maximum protection and corrosion resistance. Hard anodising is based on the same process as sulphuric acid anodising, but can produce a much thicker layer. Experts such as poeton.co.uk/surface-treatments/anodising/hard-anodising use a lower temperature and higher voltage with specialist machinery to create thick layers in hard anodising.

If you’re not sure which anodising method is right for your needs, get in touch with an anodising specialist to find out more.