1. Buy a 1/2-13 threaded rod coupler that is 1-3/4" long.
2. Use a 1/2" drill to remove about 1/2 the length of thread.
3. Cut the coupling in half and grind both cut surfaces smooth.
4. Weld on to the #5 locking pliers.

You can use the search tool to locate the other thread that describes this process better.