Not all ferro (ferrocerium) rods are created equal. Their performance can vary and one of the important factors is the striker that is used. Some ferro rods are sold with a striker which is often a piece of hacksaw blade that is painted. That coating of paint dulls the edge of the striker and can make it ineffective. In addition, the ferro rods can have their own protective coating that inhibits their performance as well.
There are several items that can be used as a striker, the one supplied by the manufacturer of course but other items such as a P38 can opener, the back side of a hacksaw blade, and the 90 degree spine of a knife. The cutting edge of the knife also works very well but is harmful to the cutting edge. I recommend taking a file or grindstone for removing the coating or smooth surface on the top spine of the striker whether a hacksaw blade or knife to sharpen it’s striking edge, then use the striker to scrape the ferro rod until sparks appear consistantly.
It’s a good idea to sharpen the edge of every striking implement. The sharpness of the striker is paramount to the performance of the ferro rod. The creation of a fire can be a critical need so it is prudent to tune up your striker to guarantee the best possible spark for ignition.