Knife steels & sparks... Some thoughts
A quick one this. I've read some confusion over the role the choice of knife steel plays with regard to it's ability to make a spark. I just thought I'd add my 2p to the confusion.
Firstly, you have to think about where the spark is comming from and the relative hardness of the two materials being struck against each other. If you are using a firesteel for example, then the material that is burning, or sparking is comming from the firesteel itself. So long as you are striking it, with a material or edge that is harder than the firesteel, then the firesteel will spark. It doesnt matter what that material is, so lonmg as it's sharp enough and hard enough to scrape of tiny fragments of the firesteel and ignite with the heat/friction of scraping. Ceramic would work providing enough heat can be generated from the scraping action to ignite the firesteel particles, stainless or carbon steel work superbly, many naturally occuring materials should work well with firesteels.
Now it gets confusing, because if you are using a traditional flint and steel, then you do indeed need carbon steel. Why? Because the material that is burning, or sparking is the steel, not the flint. The flint is harder than the steel, so scrapes off tiny particles of steel which burn. Stainless steel wont ignite in the same way that a high carbon steel will, so throws either none at all, or verry little spark.
So, for a knife blade, carbon can be used for making sparks in all situations, but if you use it with natural flint, you will be scraping material away from your knife, not with it, you will at the very least scratch it. If you always carry a firesteel, then a stainless steel knife will do just as well, providing it has a nice square ground spine that will cut into the firesteel.
The reason I posted this and as an adjunct, is because of a knew knife I just bought. I generally prefer fixed blades, but they can be problematic to carry in many situations, so I also use a small folder when discretion is the better part of valour. I bought myself one of the best regarded folding knives in the industry, a small Chris Reeve Sebenza at a price slightly higher than a Woodlore knife. The blade steel is S30V a very competent and high tech stainless alloy, that is easy to sharpen, holds a severe edge for a long time, is very tough and wont rust easily. To my dismay, when the knife arrived, the blade had a smooth and rounded spine. Even the small thumb serrations were rounded, nothing really "square" enough to cast a spark off my firesteel. I could not get it to throw a spark at all. But I knew this had nothing to do with the steel and everything to do with the lack of "biting" surface. Fortunately, I have a belt grinder and some experience in grinding knife blades, so a quick 3 minute grind of the spine left a nice quare top edge that throws a marvelous shower of sparks off the firesteel. Still a scarry thing to do to such an expensive knife.
I'm actually quite surprised that the knife is ground this way. It comes highly recommended "if you have to have a folder, then this is the one to get" sort of thing, from all those supposedly in the know. Seems none of them use firesteels.
"I feel I was denied critical need-to-know information!"
~ Burt Gummer