Aluminium does not rust, but that does not mean it needs no protection. In air it forms a thin oxide film that wears off easily and cannot take a load. Anodizing is a way to make this film thick, hard and controllable.
What happens during anodizing
The part is immersed in an electrolyte and a current is passed through it. The aluminium surface oxidizes in a controlled way, and instead of the natural film measured in tenths of a micron, a layer of tens of microns forms. The fundamental difference from painting: the coating is not applied on top — it grows out of the metal itself. That is why it does not peel or chip — it cannot be "stripped off" like paint.
Anodizing or painting
Both methods protect, but they give different results.
- An anodized layer is hard and wear-resistant, keeps the metallic texture, does not noticeably change the part's dimensions and does not fear scratches the way paint does. The palette is limited: silver, black, bronze, gold, a few saturated colours.
- Powder coating gives any colour from the RAL catalogue, an even surface and a lower price on large products. But it is a layer on top of the metal — a heavy impact can chip it off.
A simple rule: if wear resistance and a "metal" look matter — anodizing; if you need a specific colour, a large area or a budget solution — powder coating.
Where it belongs
Anodized parts are found wherever the surface is in constant contact with hands or other parts: device housings, heat sinks, machinery components, parts subject to friction. Painting is more often chosen for facade elements, structures and products where colour matters more than coating hardness.
What to know in advance
Anodizing reveals everything on the surface: scratches, tool marks and uneven grinding will become more visible, not hidden as under paint. So parts intended for anodizing require more careful mechanical preparation. Also, different aluminium alloys produce different shades — parts from different metal batches may vary in colour.
We manufacture aluminium parts in a full cycle — cutting, bending, argon welding — and will advise which coating suits your product. Describe your task through the form on the website.
