What is it?

[Tony in SD]

Buddy of mine found this in a box of stuff. The wing screws the inner shaft and the knurled knob screws the outer cylinder. No other markings other than on the wing. What is it used for?

 

[jake2]

'D' ring shackle

 

[Adirondack case guy]

Wrong, The threads would get buggered up if used as a shackle, It appears to be some kind of a clamp.------Loren

 

[grizz02]

could be a chain break to take apart roller chains

 

[Charles in Aus.]

A guess , some type of drive chain link remover.

 

[gregww]

Rivet set?

 

[Idaho Digger]

I'd vote old school chain breaker also.

 

[caterpillar guy]

Sedge for copper or brass grommets in tarps?

 

[Janicholson]

Agree. Jim

 

[MarkB_MI]

If it's a chain breaker, there must be a hole in the jaw for the pin to go through. It's doesn't look like that's the case, but it's hard to tell in your pic. Not to mention the diameter of the center pin looks to be way too big for any normal size of chain.

A grommet set seems possible, but I don't see how it would properly form the grommet.

 

[Tony in SD]

No hole in either the anvil or pistons. Piston is cupped and anvil shaped like it could hold a grommet.

 

[Ted in NE-OH]

Thumb squeezer for torchering

 

[kencombs]

Probably a tubular rivet setting tool. Used in leather work. Could also be a tarp grommet setter. Depends on the size. Rivet tool would probably be around 1/4-5/16".