Copper ring with threads on inside?

[vabuckhunter]

Found this this afternoon at a 1900 home site, seems to be made of copper but it has threads on the inside of it. Any ideas?

 

[Stegner]

The profile of the item doesn't suggest ring - look at the part of the item that should be on the palm side of the "ring" - it should be low profile but looks to be high profile.

 

[bradyboy]

is it threaded all the way a continuous thread?, start to finish on the inside
in other words, can you take a tooth pick and follow the thread to the opposite end of the ring?
if so, I would then take a thread gauge and measure the the thread size
that would be a big help
Brady

 

[Back-of-the-boat]

Maybe it was a copper nut someone shaped into a ring.

 

[Citiboy289]

Maybe it was a copper nut someone shaped into a ring.

I think that's about right People used to TAP a silver half dollar to make a ring More than likely the same idea

 

[RichieRich]

looks like a plumbing nut