Technical Article

Anodizing for Machined Aluminium Parts

Anodizing protects and beautifies aluminium — but it changes dimensions slightly. Plan for it.

Type II vs Type III

Type II (decorative) is thinner and colourful; Type III (hardcoat) is thick, wear-resistant and usually grey/black. Choose by duty.

Dimensional impact

Anodize adds thickness to surfaces — roughly half grows outward. Mask threads and bores you need to stay to size.

Design for it

Call out masking, specify the coating thickness, and avoid tight tolerances on features that will be coated.

Frequently asked questions

Does anodizing change hole size?

It can — coat builds on the surface, so mask critical bores or size before coating.

Which colour for equipment?

Often black or clear; match your brand, but remember thick coatings read darker.