There are several bottom-tier maces in Pendor, all of which possess the same characteristics: easy to find, cheap to purchase, low-to-decent damage, very short reach, and absolutely no strength requirement to use. None of these are very good on horseback, but all of them are at least decent in close-quarters melee combat.
The Iron Mace isn't very damaging, but it can't be that bad a weapon if an elite fighter like the Knight of the Ebony Gauntlet chooses it as his sidearm.
Troops that use this weapon include: