Early or mid 20th century vintage iron hardware for farm equipment, chains for a 'drag' type implement pulled through the field by a tractor or horse.
There's six chainsin this lot, 22" long end to end. The cast rings are 3 1/4" across the rims, 2 1/2" across the centers.
These would probably work as well as ever, but they'd also make great rusty crusty primitives for a wall hanging display, or hooked together or make a garland of chain. Or just to hang around in your barn or man cave!