Steel is a metal alloy which includes iron and often some carbon.
It is hard to see how the small amounts used in various metal alloys could be the source.
Now I learn that they are named after a metal alloy?
They may be made from bamboo or a metal alloy, such as brass.
The problem part, a bracket, is about six inches long and made of a metal alloy.
Seems to be a metal alloy combined with a cloth they haven't yet completely identified.
So far I've been able to work fairly well with that metal alloy.
Instead of ink, the pen writes with a metal alloy.
People who experiment with exotic metal alloys sometimes use them.
It also gives a high gloss, which metal alloys do not.