It's Gerber I believe. Hot side of a bathtub faucet. I had finished replacing the rubber washer and was re-installing the stem. After turning water supply back on, there was a drip forming where nut meets valve body and I twisted the nut off trying to tighten. The threads remain in the valve body keeping the washer end of the stem from coming out. I would like to remove the threaded end of the nut so I can replace with a new one or the entire stem assembly.