As said above, it depends on what all you are using it for. Keep in mind that any imperfections on the anvil or hammer faces are imprinted onto the metal you are working. If you are riveting, it's not a big deal but if you are forging a blade, it becomes a very big deal. With my blacksmithing anvils, I grind them smooth and rust free and then apply a light spray coat of either penetrating oil or cooking spray. Of course the best way to keep the rust off is to use them daily