Here is a steel striker that I made for a flint and steel kit. I have been making them from 1/4″ coil springs from overhead doors. It is a pretty good spring steel that works well for strikers. I keep them as hard as possible which seems to work well. At some point I might start making them from W1 and see how that works.
I made this one so that it would fit nice into an Altoids tin.
Here are a few photo’s.