for wire wheels – rawhide side of a copper / rawhide mallet. will not mark the chrome and is heavy enough to lock on the hubs with a few hits.
grain orientation on the mallets shown will mark very quickly on small cross-section steel. I would suggest a banded piece with an end-grain face. Almost any hardwood except the Australian and tropical varieties that have mineral inclusions – eg merbau – as there is always a risk they will mark the surface.
many Australian hardwoods have a very short curly grain that tends to collapse under this type of work (eg blakeleys and other red gum used for posts) so although dense, heavy and cheap, not ideal.