Got a question.

[HeelSpur]

http://www.wrenchingnews.com/industry-standard-wrenches/chart.html

I know the above chart is incomplete and under construction.
This Williams wrench looks like #513 to me, I have a 501&502 and they are small wrenches.
513 isn't listed, but I was wondering if this wrench is in the same category as the lower 500's or might it be in a category not listed. Or is it even a 513. I know the larger the # the larger the wrench but this is a big wrench and doesn't seem to fit the sequence of the lower numbered wrenches.

[rusty]

The 500 series is for set screws, and ends at 511 which is for 1-1/8, but it is also kind of a mongral series as it was recycled over other manufacturers number systems that already existed for things like s-wrenches.

Normally set screw wrenches would have a 22 degree opening, check nut wrenches would be 15 (and thin) , and engineers wrenches would be 15 and thick.

My guess is it is a machinists wrench that uses an older number system, but, williams was famous for making up non-standard standard numbers whenever they felt like it ;P

The random ding pattern makes me think machine setup wrench btw...

[HeelSpur]

What ever it was used for it was used pretty good,
like you said it is beat up.