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.
Dave
Traditional Skills - David Sims 
That’s really cool! And I love that it’s made from recycled parts too. Nice work.
Thanks for the reply.
I made a couple of those that were so hard that they broke off after several strikes with the flint. I have tried quenching them a little colder, but then they don’t spark like I think they should. Do you ever have that problem? I’ll be curious to see what happens when you try other steel. Thanks for posting!
I have not had any break from normal use. I did break one because I did something stupid. Right after quenching it got a little bend in it. I said maybe I could just tap it and straighten it out. Right as I did it, I said to myself that it was going to break, and sure enough it did.
For the most part the ones I have made are fine full hard. Quenching in oil will make them a little less hard. You can always put them in the oven for an hour at 400 and that will keep them hard but make them more robust.
Good luck,
Dave