Old key?

[wmec627]

Found this in a Kennedy tool box I bought recently.
There was a large cross section of tools and items in it.
This is one that had my perplexed.
Google says it’s a key and I suppose it is but I’ve never seen anything like this before.
It has what looks like threads on it but it’s flat.
Any ideas?

 

[RTM]

I think someone made a key out of an eyebolt. Flattened it with heat and a hammer, ground it as needed.
My ¢¢, about what you paid for it

 

[rust in the eye]

No doubt a story behind that, couldn't tell you at gunpoint what is was intended for.

 

[four.cycle]

I think someone made a key out of an eyebolt.

^ You too?
I really don't like to guess, but that's my best guess as well.

 

[dscheidt]

No doubt a story behind that, couldn't tell you at gunpoint what is was intended for.

I would guess something like a clock, not a lock.

 

[four.cycle]

clock wind-up keys are generally a square female opening - usually pretty small.