Yes. Which means the dimension of the anodised part changes. The amount of change Anodising is a process that converts aluminum to its oxide. The oxide is thicker than the aluminum that is consumed will depend on the anodising process conditions (temperature, current density, etc.) and alloy. Keep in mind that when calculating the shrinkage of a hole, you must double the amounts given because a hole has two sides. Different anodisers use slightly different process parameters. With all these variables, it is a good idea for the design engineer to contact the anodising plant under consideration and ask for their input.