hmmm, if it's not used to work the metal, it must be used to work the mold or form that's used for the metal, but I've looked at a thousand mold making tools and can't find any that have round balls on the end of them.
The fact that the tube is threaded on both ends leads one to assume that you can put two different sized balls on to choose from when doing whatever it is you do with this.
The small size and you saying I was warm leads me to think ornamental or intricate work..... jewelry searches didn't produce anything....
I have no idea what to try next. Arghhh