We have used flint and steel since the iron age. High carbon steel, to be exact, but there are more modern versions that give a much bigger spark. The steel is typically in a c shape to protect the fingers while striking. However, it can come in other shapes, such as a circle, a straight rod of about 4 inches, a rod with a single finger loop for stability, and different designs. Many modern bushcrafters, and I assume people in history, use the spines of carbon steel knives, so they do not have to carry extra steel. The downside is if anything happens to your knife, you cannot make a fire in this way. 

Carbon steel can rust quickly when in contact with water, so it is important to keep it dry. If it does get wet, you will need to dry it as soon as possible. 

Flint is a type of quartz that makes a spark when it hits steel, specifically carbon steel. Stainless steel does not make good sparks, if any, when used with flint. Something your character might not know in a post-apocalyptic world, or if they are a pampered, spoiled brat. I mean, ones that have never done this before, like a prince who was waited on hand and foot. 

Before flint was first used for fire, many cultures used flint for arrowheads, spear points, tools, a grinding stone for grains, and even ornamental jewelry. 

Some other rocks have been known to be used with steel to make sparks, such as jasper, obsidian, quartz, and chert. Most have a natural sparkle to the rock. Keep in mind that might not be what the locals call it. 

(There is a personal story found only in the audio podcast.) 

Flint and steel are used by striking the flint and steel together in a downward motion. There seems to be a division in ideas of which should strike the other. Flint strikes steel, or steel strikes flint, both sides say the other way is more likely to break the flint. 

Getting the sparks to go exactly where you mean for them can be tricky, but moving as close as you can to where you want it is helpful. This is not exceptionally hard, but as with most things, you get better with practice. 

This skill is not hard to learn but can be easier for some and harder for others. Some variables can make it harder, such as wind or how easy the object you are trying to light on fire is to take a spark. That is just a fancy way to say hot enough to catch fire. 

It is important to remember this will NOT set a log on fire. You are setting something small on fire, such as a charred cloth, dryer lint, cotton ball, dead leaves, dry grass, or even fur or hair. This burns quickly, so a small bundle of each to burn objects called a bird’s nest should be waiting. Once you have that lit or on fire, you move it to a pre-prepared bundle of twigs. The goal is to keep adding the next size stick after the last caught on fire until you have worked your way up to logs.

A well-practiced person can have a raging fire in as little as five minutes, while a beginner without guidance might take a full hour to get to the same point. 

Fun fact: Today’s lighters still use flint and steel to make sparks. This would make a great post-apocalyptic tool even after the lighter fluid has run out. 

What could possibly go wrong? 

Likely to go wrong: 

The sparks do not go where your character wants because of inexperience or wind. 

Likely to go wrong:  

The things your character are trying to catch on fire are too wet. Fresh wood is very difficult to burn because it still contains the moisture the tree needed. 

Possible to go wrong: 

The flint breaks. There are a lot of reasons this could happen. Hit it too hard, at the wrong angle, someone stepped on it, etc. 

Possible to go wrong:  

Your character cuts their finger. Remember that these were used for arrowheads and spearheads. They can be hard and sharp. If  your character holds something wrong or you slip, you could cut yourself. 

Unlikely to go wrong: 

Too rusty to make sparks. While I have never heard of this before, if the steel was heavily rusted and the character did not scrap off the rust, then this is a possibility.

Unlikely to go wrong: 

The spark goes somewhere  your character didn’t want it to and burns or lights something on fire. This would most likely, be clothing, shoes, dry leaves, or something close that is easy to burn. 

Unlikely to go wrong: 

It could also spark the fumes from gas. 

Improbable but technically still in the realm of possibilities:

The flint breaks and hits or takes out someone’s eyes. 

Improbable but technically still in the realm of possibilities:

One of those sparks goes unnoticed and sets the tent, house, or even forest on fire. 

Helpful Links to Learn More:

History:

https://www.crazycrow.com/site/brief-history-of-steel-fire-strikers-and-fire-making/

https://masterwoodsman.com/2016/flint-and-steel/

How-to Videos:

https://youtu.be/Zg65rB-z66Q

https://youtu.be/GQylF_nvLHI