How long your ferro rod will last depends on several different factors. The simple answer is that the average ferro rod will last between 8,000 and 12,000 strikes. For a normal person, this is a lifetime. One person could easily go camping several times a year for the rest of their life and still only need one ferro rod.
However, there are a few other variables to consider. The hardness of the alloy is one of them. Not all ferro rods are made the same. The softer ones will not last as long as a harder alloy. The thickness of the ferro rod is another factor that matters. The more alloy material that you have to work with, the longer it will last. Finally, the skill of the user will also affect how long the ferro rod lasts. People new to fire starting will often dig into the ferro rod thinking it will get them more sparks. An experienced user will use less pressure to achieve the same result.
The real factor that will determine how long your ferro rod will last is how long you will take to lose it. Ferro rods are generally small and easy to misplace. If a ferro rod is dropped in a pile of leaves, you may never see it again. I think in all my time using ferro rods, I have probably lost at least a dozen of them.
There are things you can do to avoid losing your ferro rod. You can put it on a lanyard and keep it around your neck when you aren’t using it. I have found this to be very helpful, and I attached lanyards to most of my ferro rods. Also, if your ferro rod is not hunter orange then you should make it so. Use hunter orange paint or tape or make the lanyard hunter orange. This color will stand out much better than the standard colors you will see for ferro rods.
Finally, buy two at a time. I almost always keep two ferro rods with me when I am in the wilderness. They are only a few dollars, so you might as well have an extra one just in case you need it. I like to keep one around my neck and one in my pack at all times. If you are in a pinch and need a fire, you will be happy you brought them.
Want to learn how to use a Ferro rod properly? Here's an in-depth explanation
Want to get your own Ferro Rod? Here's your best option