It's a filings vise. This one is copied by one owned by Clay Spencer. This was made by a couple of friends, one with a water jet company and the other with a machine shop. There is one pictured in the Blacksmiths cookbook on page 19. I also have one from Kayne and Sons. these are great for filling edge bevels and also for thin stock so you can see the profile while you file. It would be handy to have several with different angles on them. This one is about 45 degrees.
I'd post a picture but I can't figure out how to get it uploaded here.
