WTH is this?

[njsteve]

You may want to post here: https://www.garagejournal.com/. They are great at identifying bizarre old tools. I went down a mile long rabbit hole trying to ID a couple of bizarre unadjustable torque wrenches that i found in my Father-In-Law's tool box and learned they were made by a company "Jo-Line" that supplied WWII military production factories with calibrated screw drivers, and wrenches for repetitive assembly work to precise tolerances. In a total fluke of coincidence the son of the son of the original inventor found the thread and started filling everyone in on these amazing tools. The man's grandfather was a mechanical genius and held the patent on the micrometer-based torque wrenches we all use today. He would confer with his nearly 100-year old father and post the stories of the goings-on at the factory back in the 1940s to the 1970's.

These two wrenches were prototypes for future production made for one of their reps in Chicago. One was calibrated to 50 inch pounds and the other to 75 inch pounds.

Here's the thread on the Jo-Line wrench story with 70-year old the son chiming in after discussing the tools with his then, late 90's aged father: https://www.garagejournal.com/forum/...enches.413693/