The punch pin on the Hole Punch Pliers can dull down over time or break if you try to punch through something that is too thick. The beauty of this tool is the pin is easily screwed out and replaced. The plier comes with one replacement, but if you need more, here they are in packs of 5.
Having spares when you're in the middle of a big batch of hole punching is key! I didn't realize how dull mine was until I switched it out with a fresh punch!