Phase 1 of hardening the sleeve drive pin is to get it to a bright red heat. The butane blowtorch I tried wasn’t enough for the job, so I I bought a butane/propane mix. That was much better and with a few bricks around to reflect the heat it was soon glowing.

The photo looks like a space raygun about to vaporise something. Maybe I watch too much SciFi?

Next to quench it in oil.