The Ironfists were one of the Houses of the seven Fathers of the Dwarves in Middle-earth. Presumably, as they do not appear in any of the tales, they lived far to the east in the northern range of the Orocarni mountains where they were paired with the Stiffbeards. The Ironfists were said to be greedy, xenophobic, and warlike clan.
A character in the popular Neverwinter Nights series of games based in the D&D universe is named Khelgar Ironfist. His name is most likely a tribute to Tolkien.