Have this cast wrench.   No names, numbers or stamps.  Over two inch jaws.  For size, that is a 12in. crescent in the pic.   I think it is oddly short for jaws so big.   Check nuts?   Steam fittings, packing?  Ideas?

Gotta be the biggest S wrench I have seen a picture of. 

That's a very large S wrench, John. They are a patented tool for tightening large S's

QuoteThey are a patented tool for tightening large S's

But then they would be 8s!