Thought I'd go ahead and post a pic of my flint and steel fire kit:(Image removed from quote.)Char cloth is at the bottom of the box. Hardened steel striker. Nice piece of flint. Waxed and unwaxed jute for tinder. The unwaxed works better for igniting with an ember; the waxed is brilliant for catching and holding a flame to get a fire started. And the waxed is more water-resistant. Which can be nice. It's very important to have a large and loose bundle of tinder for the ember to 'nest' in, so the heat can build up, and oxygen can keep the embers burning. In addition to flint, one can use hard chert or obsidian with good results.
(I do suspect throwing nice sparks from stainless may be harder than from carbon steel, but I haven't tested and haven't got the necessary theoretical knowledge. I'm just thinking of all the chrome possibly protecting the “flammable” parts.)
420 HC is high carbon, but it's still a stainless steel