I found this at a late 1800's home site. My first guess was some kind of decorative nut, but I've looked and I just really don't see any threads in the center hole. There are two "edges" on the back like maybe it was intended to have a rail or board or something in between. It's pretty thick and heavy, iron obviously, with no visible identifying marks. The only thing I've seen that kinda resembles this is a retaining nut on a lateral restraint on old brick buildings -- but there again, it does not appear to be threaded. Does anyone recognize it?



