I was in the garage, loosening a stuck rusty garden hose nozzle, when I grabbed that familiar blue-and-yellow can of WD-40. As I sprayed, it hit me: I’ve been using this stuff for decades, but I had no idea what “WD-40” actually stood for.

We all say it without thinking—“Grab the WD-40”—like “Pass the salt” or “Turn it off and on again.” It’s part of the fixer-upper language. But the name? Completely mysterious. That curiosity led me down the rabbit hole.

The Cold War Origins
Here’s the cool part: WD-40 traces back to 1953. Chemist Norm Larsen worked at the Rocket Chemical Company. Their mission? Create a formula to prevent missile parts from corroding. Not for squeaky doors or stuck bike pedals—real Cold War missiles.

Larsen and his team experimented with water displacement formulas. They failed 39 times before perfecting the 40th attempt. And that’s the name: WD = Water Displacement, 40 = 40th formula. No marketing gimmicks. Just plain, geeky truth.