Heart of the Oak Runeword in Diablo II: Resurrected Wowhead
Putting this Runeword in a Hammer or Mace will fail. ONLY those weapons designed Mace by the Runewords system will work, and 2 of the 3 of these types do not have enough sockets to hold this Runeword. Therefore, ONLY the onehanded weapons based on the Flail the stick with the chain and ball will work for Heart of the Oak..