Sulphuric

Best known as a cosmetic finish in that it is 0.006mm per surface and has a luster finish to enhance the final product at the same time sealing the aluminium from the elements.

Ammonia Bronze

Typically used to take the shine from brass components or to add an aged appearance.

Hard Anodise

For more hard wearing properties and usually has an etched surface for consistency . The anodize here is usually to a depth of 0.013mm per surface.

Perfect for hard wearing component use where friction is critical, provides a coating of PTFE to standard hard anodize allowing moving components to move more freely whilst reducing the damage over time by such movement e.g. bearings.

Alchromate

Not entirely for protection but a very good base for paint or other suitable finishes whilst at the same time sealing the component.