Axes won't actually be owned by anybody; they're fort property.
Other possibilities... Are the axes accessible? Are the woodcutters holding the axes? Might you have, foolishly, decided to make your woodcutters into axe-wielding militiamen (which doesn't work as you'd expect)? Might you have other axe-wielding militiamen who may be holding them?
To find the answer to the first, second, and fourth questions, enter the stocks screen, scroll to your axes, hit TAB to expand the list to see individual items, then hit z to zoom to the axe. If it's being held by a dwarf, it will zoom to the dwarf but won't show their inventory.
The reason why woodcutters don't make good militiamen is that the woodcutter job assigns an invisible pseudo-uniform that happens to contain an axe. If they're assigned to the military and set to wield an axe, they'll seek a second, different axe for their military uniform from the one they use for civilian work. When they go on-duty, they'll drop their civilian axe and seek an axe that isn't claimed for anything, including other woodcutters' civilian axes and other soldiers' military axes, and similar will happen when they go off-duty. If all the axes are claimed as military axes, your woodcutters won't have any axes available for civilian work.
The short of this is that you need 2 axes for every woodcutter/axeman. 2 woodcutter/axemen and 2 axes means you don't have enough.