It's much easier to cut such a thick piece of metal using a blade with 14 or 18 teeth per inch. Teeth per inch is abbreviated as TPI. The same holds true for cutting something thin, like sheet metal.

I open a lot of boxes and cut a lot of cardboard. I used to use knives with metal blades -- from penknives to the ubiquitous Stanley box cutter -- but found that cutting the card and tape would ...