Bench Buffer Threads

[aalligood]

I bought a bench grinder at an auction and they threw in a bench buffer that was mounted to the same cart. The data plate has specs but the manufacturer is worn away. Both shafts appear to be right hand threads. One shaft is definitely 1/2-20 thread (pictured with hex nuts). The other threads are in rough shape but appear to be 18 tpi. I did some research and 1/2-18 isn’t unheard of, but I’m not sure what’s going with this.

Any thoughts?

Also, I do have the mount. I had already started disassembly when I discovered the thread mystery.

 

[The Cobbler]

it looks like the LH shaft might be an arbour attached to the original shaft ?

 

[aalligood]

You were correct. The 1/2 20 threaded shaft was an arbor. I heated the spacer on the other shaft (it was threaded) and it came off and cleaned up the threads somewhat. I may take a shot at making some 1/2 18 bolts. I believe this may actually be an old refrigeration motor that someone repurposed.