Any ID on this hunk of iron?

[TampaTroy]

When I dug it up near the river I assumed it was a square nut from the old bridge that was nearby. I tossed in the back of the truck and after a rain washed some dirt away it looks like this. It still might be an old nut but now I'm not so sure. It's just junk but if I knew what it was it might lead to better junk. Any IDs?

 

[Hawkeye35]

I'm guessing it's part of a cable anchor system from the old bridge.

 

[duggap]

I'm guessing it's part of a cable anchor system from the old bridge.

Or off a railroad possibly.

 

[digging wv]

Transformer or relay core? Is it made from layers of metal? Looks like it might be from photo on the right.

 

[bradyboy]

Could be a pipe threading die head
Brady