If you bring a pocket knife to school you will most likely be expelled and might even end up arrested. But somehow nobody bothers to mention how school supplies can be very dangerous. This includes those giant scissors that are litterlly two knives connected by a screw, math compasses that can easily be used to stab someone, and or just plain old pencils. They can cause serious infections (although thankfully they aren't made with lead anymore) and will leave a mark that stays for years. This is because although graphite is almost harmless, it won't just disappear. *Pencils are very dangerous as even John Wick was able to kill 3 men in a bar with just a pencil.
If you haven't realized yet, pencil sharpeners all have razors that can be removed and cause quite some damage.
Some rulers have a metal strip. A METAL STRIP! As if you seriously need that metal strip to draw better lines. More likely than not, it will mess up your lines. Getting wacked on the head with a wooden object would hurt, but once you add a metal strip you'll most likely see blood.
Then there is a large assortment of objects that can be brought to school without getting into trouble like screwdrivers and bricks (nobody would question it if you said it was for art class).