For reference this is a 5/8 lock nut with an Allen screw inside. It was so seized up, we let it soak for 3 days with antiseize, tried head and freeze method, and nothing helped. Still ended up with a stripped screw. I’m at a loss at this point and not sure I feel comfortable grinding a notch into it.
You can try and hammer in a torx but that’s slightly larger and see if it will turn if not or if you are trying to turn just the shaft and not the nut clockwise maybe you can try a capped nut
That’s not a bad idea. It’s a lock nut so it has to be loosened first in order to get the screw free, so it’s kind of a pain in the ass. The torx isn’t a bad idea. I thought about rec welding an Allen key into it and just leaving it but I decided against that idea for now.