How to connect 2 pieces of galvanized pipe when the threads are stripped

Here we had a dilemma. The new bathroom plumbing was all ready to go but the galvanized hot water supply line was in bad shape. The threads at the connection end were badly corroded and stripped, and the pipe would not budge when we tried to remove it. I set off to Home Depot and asked the plumber lady what we could do to hack this into working. She suggested using 2 galvanized compression couplings. Unfortunately, the only couplings in stock at Home Depot were too large (pictured) but I was able to find ½" compression couplings at my local plumbing supply store. They worked great. In the end though, I ripped out all the galvanized pipes, returned all the parts, and started fresh with PEX, which I ought to have just done in the first place.