This must be one of my oldest forum tutorials. A carbon knife and flint duplicates a flintlock firearm. The molecules of carbon in the knife are the combustable material. The Rockwell hardness is necessary for the flint to percus the carbon. Anything softer and it will merely dig in. This really should be a backup method and not your primary strategy. You are in effect degrading the cosmetics of your knife. The carbon Moras, with the spine properly dressed are again superb training knives. You might also consider buying a period flint and steel firemaking kit. So called metal matches simply reverse the roles and again can cause a degree of cosmetic damage. With metal matches a section of hacksaw blade is a superior striker. So practise with a $9 Mora, try it once proficient on your Benchmade and buy a few Bics with the change.