A ferro rod is made of a combination of metals containing iron, praseodymium, neodymium, magnesium, lanthanum, and a rare earth called cerium. It also includes a steel striker. The pyrophoric effect (ability to ignite) comes from Cerium and iron.
While the exact composition of ferro rods is different depending on manufacturer, the main elements will always be iron and cerium.
Main elements of a Ferro Rod
The original ferrocerium (created by Carl Auer von Welsbach in ) was composed of 70% Cerium and 30% iron. That composition has changed in modern times, but cerium and iron remain the key elements of ferrocerium.
Ferrocerium is what you’ll find in flints in the common lighter.
The “ferro” in ferro rod means something contains iron. So that’s where we’ll start.
Iron is highly conductive and a good transmitter of heat. Iron is a pyrophoric- when exposed to oxygen, it will create fire. The oxidation process of iron is what gives off heat and produces the fire.
Ferro rods with more iron content are known as hard ferro rods, and they will tend to last longer.
The “cerium” in Ferrocerium comes from the metal that was discovered in 1803. Cerium is a soft rare earth metal that is used in ferro rods because of its pyrophoric properties. It is the key metal in an alloy called mischmetal, which is a combination of metals that is used often for lighter flints.
Cerium is a great element for fires because of its low ignition temperature of between 302 and 356 °F.
Besides being used in ferro rods, it is used in polishing windows and as a catalytic converter in cars.
Lanthanum is a rare earth metal that was added from the original ferrocerium composition. It is basically a very sensitive form of magnesium that is easy to spark. Its first application since its discovery was, hence, lanterns.
Nowadays it is normal for ferro rods to be made up of at least a 25% lanthanum.
Magnesium is part of the “special alloy” that is sometimes added in small amounts to get bigger sparks. Special alloys, with magnesium and zinc as key ingredients, were used in the past for miners’ lamps.
But magnesium- based ferro rods will tend to wear quicker than those with more iron.