There’s a chance that this Germanic-origin word originally means something to do with stone – OED says “stone weapon”, but I am thinking that one woman’s weapon is another woman’s nail-whacking tool…
For a work with so many dwarves in, I am surprised by how little the word is used in The Hobbit.
• 1.074 While hammers fell like ringing bells
• 4.020 Hammer and tongs! Knocker and gongs!
• 4.025 Hammers, axes, swords, daggers, pickaxes, tongs,
• 12.096 hammered and carven with birds
• 15.038 While hammers fell like ringing bells
“hammer, n.1.” OED Online, Oxford University Press, September 2019, http://www.oed.com/view/Entry/83743. Accessed 9 October 2019.