Nice job Waylander
, there was also another type with a steel mounted in wood and I was recently commissioned to make a couple of blades to be incorporated into a leather pouch which should be interesting.
By heating the steel to yellow you are increasing the grain size (good for sparks) and then such an aggresive quench will leave the steel very hard, also good for sparks, unfortunately this isnt possible with all firesteels. You can get away with it with a file and if you just want sparks a file is the best material for it with I suspect mostly similar composition to my favourite Stubbs silver steel but with the more popular forged C shaped steels the decorative arms would be left very fragile. You should get a similar result if you heat the steel to yellow, hold it there for a while to increase the grain size then allow it to cool to just above non magnetic before quenching and luke warm water is fine