Misterg
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approx 0.06mm, so 0.03 per side, not sure what it is meant to be.
You should get 0.2 microns per minute of anodising at 6A/sq foot (6mA / cm^2).
The process eats the original surface away slightly, so about half of the anodising thickness is proud of the original surface, and about half is below the original surface.
An hour at 6A/sq foot should give a layer thickness of ~12µm which would also increase the part dimensions by 12µm (2 surfaces affected, half thickness on each).
I aim for 12µm as a minimum, or 25µm if I want to dye it (black, especially).
In practice, the dimensions are also affected if you do a pre-anodising etch in sodium hydroxide - this isn't as predictable (heavily dependent on temperature and the thickness of the oxide film on the original parts), but can be of the same order as the dimensional growth during anodising, so you may see no net change.