WD-40 stands for “Water Displacement, 40th formula.”

Quick Scoop: What does WD-40 stand for?

  • WD = Water Displacement
  • 40 = It was the 40th successful formula during development.

In other words, the name is literally describing a product designed to push water away and protect metal from rust, and it only worked the way they wanted on attempt number forty.

A tiny bit of backstory

  • WD-40 was first developed in 1953 for the aerospace and missile industry to prevent corrosion by displacing moisture on metal surfaces.
  • The formula proved so useful that it was later sold for general household and industrial use, becoming the classic multi-purpose spray people keep in garages and toolboxes today.

So when someone asks “what does WD 40 stand for,” the precise answer is: Water Displacement, 40th formula.

TL;DR: WD-40 = Water Displacement, 40th formula — named for what it does and the number of attempts it took to get it right.

Information gathered from public forums or data available on the internet and portrayed here.