Hammers = War Hammer, Maul, Great Maul, and Exceptional/Elite versions. These will not work in mace recipes even though they are listed on the mace page.
Maces = Mace, Morning Star, Flail, and Exceptional/Elite versions. This does not include any other types of Maces. Make sure you read about Hammers above. They are not "maces" in the case of Runewords.