I carry ferro rods in all my kits. They are also very good for lighting gas stoves and alcohol stoves. I love making fires with ferro rods and practice on many types of tinders. I still use a lighter of course, but my ferro rods are 100% dependable with skills and knowledge on tinder prep.
Many beginners have bad luck with the ferro rod because the scraper that comes with it is often useless, or next to useless. They make feeble sparks, which will not ignite a difficult tinder. The edge has to be a sharp 90 degree spine. If its not, then you cannot rip molten metal globs off it, which is what you want for many natural tinders. Gas and alcohol stoves only need small sparks, but many natural tinders in the bush need a glob of molten metal that will last for a good second or so.
You can file the spine on a poor striker to be a sharp 90. Or some knives are specially designed with sharp spines to rip metal off a ferro rod, like the F1. Moras are infamous for having rounded spines, but they and most knives can be modified easily with some filing of the spine to be ferro rod strikers. The new Mora "bushcraft" models have sharp spines for just this purpose, and also for making fine wood shavings, which make tinder for a ferro rod spark. I highly recommend a sharp 90 degree spine on all outdoors knives anyway.
I have replaced most of my strikers with the carbide ones from Firesteel.com. These are excellent, and they only cost a buck or so. I mass order them to justify the shipping cost (many dozens at a time) and give them as gifts, and I have a class set of ferro rods with these strikers that I use for teaching firecraft. Need a stocking stuffer? - give a striker. Heck give a ferro rod and striker! You can never have too many for various kits in home, vehicle, bush, survival kits, PFD, backup, etc.
Folks above have mentioned ”ferrocerium and "mischmetal". As I understand it, its all "mischmetal" in various compositions, with iron and cerium being key elements in various proportions along with others that have been mentioned above. I have found it more instructive to describe the various brands as harder or softer. The hardness determines how you strike it to make various types of sparks and molten globs. The hard ones you can strike quite slowly to generate sparks. The more pressure you apply, the bigger the molten globs get. The softer ones require a faster strike, and they produce molten globs easier, but perhaps with less ability to aim, although that is an acquired skill that can be refined. With a slow scrape on the softer ones, you can also produce a pile of metal shavings that do not ignite. Then you fast strike it and can ignite the pile for a bigger hotter longer burn. The two extremes of the spectrum in hardness are very different in their behaviour with the strike, but both can be equally effective when you adjust your technique.
The harder type is well represented by the Swedish "Light My Fire" brand – in fact it tends to be the benchmark that others are compared to for hardness. The softer type is well represented by the "Firesteel.com" brand. I own both, but I have to say that I prefer the LMF type a little better, but that is just me. They are both great brands and both great compositions. That said, I dislike the strikers that come with the new LMF ferro rods. I replace them with a Firesteel.com carbide striker.
Once you get to know and love using ferro rods, you will start to know which of your tools have an edge that makes a good striker. The best I have is the spine of my F1, which produces ultimate molten metal globs, its incredible. The back of saws on multitools are often also very good. The awl that folds out to the end on the alox SAK's is superb. The side folding awl on a SAK is in too awkward a position for me to use a striker. Although a knife edge will make a fine spark blob, you don’t want to do that and dull the edge. An axe edge can be used since its not as critical for sharpness as your knife, and can be touched up easier.
For my teaching class set, I bought the cheapo Coghlans ferro rods (since I could not afford a class set of the better brands). The strikers that come with them were literally rounded and completely useless so I cut them off the lanyards. They could be filed into 90 edges, but I already owned dozens of the Firesteel.com strikers, so I re-attached them with longer lanyards. The superb carbide strikers make the Coghlans a decent ferro rod, (although I would not trust their quality control – better to go with the better brands )
The strikers often come with too short a lanyard even on the better brands. I cut the lanyards off and make longer ones which give you a roomy full grip with plenty of slack for a good strike.
Now, get out there and make some fires! Warning – ferro rods can become addictive. I often go out at night in my back yard, scrape up some birch bark into fine shavings, and rip a few ignitions with the F1, just because its fun and makes me feel good! In the bush I am always collecting new tinder material to try out. My favourite (other than birchbark), is balsam fir gum mashed into uznea arboreal lichen, which grows on balsam fir, and acts like a wick. It burns for many seconds to a minute or more depending how much gum and lichen you have mixed together.
