Next time you're in the hardware store grab the biggest nail you can find and sharpen the point on a grinder. Put some type of wrap or heat shrink tubing around it on the back end. You just made something more useful than a plastic knife. It's likely galvanized so it's protected from rust. If it does happen to rust, scrub it off with sandpaper, or better yet give your attacker tetanus for that extra +1 damage.
I'm starting to wonder if the designers carry and use knives, or just sit in front of CAD all day.