Found this AMMCO tool-post / machine wrench. My guess is that it's for one of their brake lathes or shapers. I dug around a bit and all I found was that at least some of their shapers came with single-ended wrenches - so that was no help.

This 5/16" - 3/8" DOE is 5.1 inches long and the maximum jaw thickness is 0.375" - a stout little ******.

This 5/16" - 3/8" DOE is 5.1 inches long and the maximum jaw thickness is 0.375" - a stout little ******.





