For the 6497 stem you want to cut as much of it as possible before hardening and tempering it. Working hardened steel is much more challenging and necessitates different tooling than raw steel. Since the stem is such a small and detailed component it's very easy to break, especially when cutting the slot out. The quenching after heating for hardening is one of the more challenging aspects, if your quench technique is off or something happens and you don't quench your stem straight up and down, it'll warp - and your stem will be rendered useless.

Bringing the stem to a polished finish is also essential, polished surfaces that are interacting with other parts will wear less, have less friction and as a result, last longer. Above you can see my stem with polishing compound on the end of the threads, I'm about to thread it into a piece of wood with a tight hole to try and polish all surfaces of the threads. At this step I will make any final cuts necessary, make sure my surfaces are flat, edges are 90º and everything is polished.

A fun exercise with skill training that transcend the fabrication of stems, though, for a days work I'd probably end up paying $6 for a replacement stem ;) .

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