You're wrong, it's a pipefitter's tool, iron fittings are all over the place size wise. The old Williams adjustable Superwrenches were blunt and heavy. Not so handy, but tough. If you find them at a fleamarket, pick them up. We used 15" wrenches a lot, you can't carry a toolbox around with you in a mill, but you can carry a 15" . The best one I had was a Procraft, but sadly it was stolen . They replaced it with a Proto. Most of the later made-in-USA wrenches had the same pattern suggesting the same factory.
Bahco claim to have invented the adjustable wrench, they might be right. Except for the backwards screw, they are good wrenches.
A simple test, pick a wrench up, shake it and, listen to the rattle.