WD-40 is a seemingly all-purpose lubricant, degreaser, and water displacer that has helped people loosen stubborn bolts and silence squeaking hinges for decades. There's an old saying that if you need ...

We may receive a commission on purchases made from links. If you've ever needed to unseat a stubborn screw or grease the track of a sliding-glass door, chances are good you've used a can of WD-40 to ...