Bending Anodised Extrusions

Bending Anodised Aluminium Extrusions


Bending Anodised Extrusions can add a stunning look to a structure or installation. The unique anodised finish compliments bending aluminium very well. Naturally, when creating a product that is anodised, the question is whether to anodise before or after bending.


Anodising Before Bending


Forming pre-anodised sections is possible but is not always recommended due to the crazing it can cause.

Anodised sections have an incredibly tough outer layer that has no elasticity;  the result after bending is micro cracking or hazing of the protective anodised layer. This shows up as a change of colour in the stretched bend zone.


Anodised aluminium section Crazing



When to anodise, before or after?


The simple solution to this risk is to simply anodise after bending.

Alubend recommend for external applications, anodising should be processed after bending to enable the coating to give 100% performance.

For internal applications where the ‘colour change’ of the crazing is not so important, bending anodised bars is possible and reasonable.

Once thing that must be checked is the tank size for anodising, as curved parts will need larger dimension tanks to accommodate their shape.


If you have any more questions about surface treatment, please refer to our information page for an additional whitepaper.


Why is Surface Treatment important?


While in some cases using untreated aluminium might be perfectly fine, there are reasons to treat the surface.

Aluminium, like other metals, can corrode when left untreated. The surface reacts with water and air and breaks down, often as a fine powder. This can slowly wear down a part and make it structurally unsound.

If kept in certain conditions this wont be a concern, but generally treating the section in some way is far better than simply leaving it untreated.