In 1953 a small lab in San Diego called the Rocket Chemical Company was trying to make a spray that would stop rust on parts of nuclear missiles. Their chief chemist, Norman Larsen, kept tweaking the recipe. The first formula didn’t work. Neither did the second, third, or twenty-second. He kept labelling each batch.
On the 40th attempt, he got it. The blue and yellow can has a tongue-in-cheek name baked into it: WD stands for “Water Displacement” and 40 is the number of the formula. The company never even bothered to give it a fancier name.
Workers at the plant started sneaking small cans of it home to oil squeaky hinges. Larsen realised they had a useful household product. Today WD-40 is sold all over the world, and the exact recipe has never been patented. Instead it is kept secret in a bank vault, so rivals can’t copy it.
