Here is a steel striker that I made the other day for a flint and steel kit. I make these from 1/4″ and 5/16″ round stock. I obtained quite a bit of this steel from overhead door coil springs. It is a good high carbon steel that works well for strikers, punches, carving tools, etc. I am able to get it pretty hard which seems to work well for making steel strikers. The thought of making them from W1 to see how that works has crossed my mind, but I have thousands of feet of the coil springs so I will probably just keep using that.
I made this one so that it would fit nice into an Altoids tin. It fits my hand pretty well this size too.
Thanks for looking, and let me know what you think.