Thanks for the info. Now that you both mention it, I seem to recall something about stems being filled. Probably should have asked the question before I cut the "valve" off of the stem. Fortunately nothing happened. What I want to do is use the stems for chasing/repousse tools. The length and diameter are comfortable in my hand. I have typically used drill rod etc but if you make dozens of tools that can get expensive. I saw an article about a European artist using old valve stems. The stem is forged/ground/shaped/polished on one end according to the need at hand. Since they are typically used on soft metal, heat treatment is generally not necessary, but I may also want to use them on steel. Hence the question about the type of metal.
As always, appreciate the help.
Ken