[tom hyle]

I'm pretty sure it's a reamer/auger for wood. It's simplest use would be to enlarge/round existing holes. It would also produce a given taper in the hole, which would match to standard plugs or stopcocks. It could be used to create a hole, with some slight effort, but ones intended to so do more commonly have a screw-tip that "draws" them into the wood. Some tools are indeed just ever so weapony, aren't they? I saw some kind of large push-dagger probably for gardening on ebay, but it went too high for me.....