Welding/cutting torch packing seals.

[Highpower]

No, I figured you were just suggesting something 'softer' than the Teflon you have.  I can guarantee that Lincoln/Harris won't even want to discuss it much less give out any details. Whatever - I've give it a shot with some PTFE and see what happens. I was just hoping someone would spill the secret recipe.  

I'm sure they used a solid/molded seal for a reason so I'll stick with that. It definitely has a step in it that seats into a slight counter bore where it threads into the torch body. The material in the new replacement seals (valve stem assemblies) are a dark brown / almost black color. Just wish I knew what it is...