"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." So next time your zipper acts up, don’t panic, and don’t automatically assume you need to toss your item.

Gear-obsessed editors choose every product we review. We may earn commission if you buy from a link. Why Trust Us? If Your Zipper Is Stuck If Your Zipper Splits Open If Your Zipper is Misaligned If ...

When you push or pull with a simple machine, you are applying a force and doing work. And, if you get more force out of a machine than you put into it, then that machine has a mechanical advantage.