WD-40

WD-40 is the trademark name of a water-displacing spray widely available in a variety of retail outlets. Developed in 1953 by Norm Larsen, founder of the Rocket Chemical Company, San Diego, California. It was originally designed to repel water and prevent corrosion, and later was found to have numerous household uses.

WD-40 stands for Water Displacer. Larsen was attempting to concoct a formula to prevent corrosion, by displacing the standing water that promotes it. In the process, he arrived at a successful formula on his 40th attempt. WD-40 is primarily composed of various hydrocarbons.

WD-40 was first used by Convair to protect the outer skin of the Atlas missile from rust and corrosion. The product first became commercially available on store shelves in San Diego in 1958.

WD-40's formula is a trade secret. The product is not patented in order to avoid completely disclosing its ingredients