Different surface treatments impart different properties to the finished component and sometimes different properties are required on certain areas of a single part. For example, it may be necessary to have a small area for electrical contact (earthing point) on an otherwise anodised (and therefore electrically insulated) part; or a part has wear surfaces that would benefit from the increased wear resistance of unsealed hard anodising, whereas the rest of the part requires the enhanced corrosion resistance of sealed anodising (which could be chromic, sulphuric or hard).

Selective anodising makes it possible to combine the properties of two separate treatments on the same part.

Selective anodising frequently involves manually masking each part before the different treatments are applied – this is likely to increase the cost and turnaround time.

An alternative method is to spot face or re-machine the part once it has been anodised to remove unwanted coating and then re-submit the part for conversion coating, or another variety of anodising, of the bare surfaces. This table summarises the advantages and disadvantages of each method.

More Info and Specialist Advice

Please email us if you would like advice on the possibilities and applications of selective anodising. This page just gives general suggestions and our specialists will be able to provide more in-depth information.


This page is provided for information only, it should not be considered advice and we cannot accept any responsibility or liability for your use of the information on this page. The information on this page is used and relied on at your own risk and you bear the sole responsibility for any outcomes. E&OE.