Ferrocerium — it's a word that sounds like it should describe the contents of a pill bottle from the drug store, rather than a tool in your survival kit. Adding to this confusion, ferrocerium rods or “ferro rods” are referred to and associated with a myriad of other terms: fire steel, metal match, magnesium rod, mischmetal, Auermetall, flint, or artificial/man-made flint. A quick search on Amazon.com reveals products with various combinations of these names.
So, what the heck is ferrocerium, and how does it work?
The substance now called ferrocerium was invented in 1903 by Austrian scientist Baron Carl Auer von Welsbach, pictured above. Welsbach was experimenting with types of mischmetal — that is, combinations of rare earth elements, such as cerium, lanthanum, and neodymium. Cerium was especially notable for its low ignition temperature.
When Welsbach mixed a combination of 70% cerium and 30% iron, he noticed the resulting alloy gave off sparks when scratched. When ferrocerium is struck by a hard and sharp object, such as a carbon steel blade, tiny shavings are oxidized and ignited by the friction of the striker and burn at 3,000°C/5,430°F.
Chemistry students may remember that iron compounds use the prefix ferro due to iron's Latin name ferrum. Therefore, this new iron-cerium alloy was called ferrocerium. Some European countries still call the material Auermetall after the baron's first name.
Later on, Welsbach added other metals to ferrocerium in order to fine-tune its properties. Lanthanum created brighter sparks, and other metals made the alloy harder and more durable. Since then, material scientists have continued to modify the recipe, producing a substance with the following approximate makeup:
Notice that ferrocerium contains magnesium. However, it's inaccurate to call the alloy a “magnesium fire starter” due to the extremely small amounts it contains (about 2%). Actual magnesium bar fire starters contain a large block of pure magnesium, which can be shaved and ignited with a ferro rod.
It's also technically inaccurate to call ferrocerium “flint” because it has no chemical relationship with the rock/mineral of the same name. However, since both ferro rods and flint rocks spark when struck against steel, ferrocerium is often called flint or artificial flint. The “flint” insert in a Zippo lighter, for example, is just a tiny piece of ferrocerium.
Not even the name “fire steel” is technically accurate, since ferrocerium contains no carbon steel, only iron or iron oxide. “Fire iron” would be a more appropriate name, but doesn't quite have the same ring to it.
No matter what you call it, ferrocerium is an excellent tool for fire-starting in survival situations. This time-tested alloy generates showers of white hot sparks on demand, and is worthy of a place in just about any survival kit.