It is a ratchet socket, thus it tightens and loosens, but on a specific common object. You are warm, however.

It is a mechanic's tool.

It's got to be for setting a spring, right?

I will accept that. It is a wheel bearing locknut adjustment/removal socket tool for post 1959 ford pickups.

I was thinking along those lines too. It looks like it would fit the tits on an axle.

that would be used to shape metal rods

It's got to be for shaping metal of some sort. If not, why the rollers? It's clear that something has been running between the 2 pins and into the rollers.