What is this?

[Baby Grand]

Turned up after tilling last year's tater patch:



Some sort of snap shackle - looks like it may be military? Material is bronze, I believe. No oxidation. This is how it looks after being dusted off after who knows how long in the soil. A drop of oil and the action is still smoooooth.

 

[boatyard]

It looks like a sail shackle. The are usually sewn or lashed on to the edge of a sail, usually the jib or staysail. It is then fastened to the forestay. I will try to dig up a photo and post it.

Your's is old school like the ones we had when I was a kid. The only ones I have found so far are a bit different. Here are the links http://www.sailrite.com/Snap-Bronze-1-Sew-On-2

http://www.jamestowndistributors.co...?pid=58483&familyName=Suncor+Bronze+Jib+Hanks

 

[165masseyky]

Turned up after tilling last year's tater patch:

View attachment 240087

Some sort of snap shackle - looks like it may be military? Material is bronze, I believe. No oxidation. This is how it looks after being dusted off after who knows how long in the soil. A drop of oil and the action is still smoooooth.

Looks like something i saw once. I think you got the shackle part right but i am thinking more like a chain gang or restraint type shackle. One that would be braded into place.

 

[North Country]

For those wondering why it looks like it does, it's designed to be able to release under load. That one's old - today's are a slightly different shape and pop open more easily.

 

[Baby Grand]

Boatyard - I never thought that it might be nautical. I'd just assumed either some sort of strap from a gun sling or hitch to a mule or horse drawn plow. Considering the material, though, I'm thinking it may be boat related.
Here's the other side:



I believe the number is B48(9?) - looks like someone filed away under the spring loaded pin on both sides to make it easier to grab & release.
The logo looks like an "L" inside a triangle inside a circle, ... or a single masted sailboat.