If one were to look back at the history of WD-40 and how it got its name, it will be seen that WD-40 was used as an external solvent that was used to prevent the Atlas missile from corrosion and rust. WD-40 stands for water displacement 40th attempt, which hasn’t changed from what it was first named as by the chemist who was working on this solvent. The formula as the name suggests, is a solvent that prevents corrosion took about 40 attempts to perfect.
The WD-40 is the trademark name that has been given to this water displacing spray. Norm Larsen is the chemist who found this and was originally planned to repel water before it was realised that there are lot of different household uses for this solvent.
One of the most active ingredients of this solvent is viscous oil which isn’t volatile and therefore floats on the surface offering protection and lubrication from moisture, thereby preventing corrosion and rust from setting in. In fact, this is further diluted with volatile hydrocarbons to give fluids of low viscosity that can penetrate crevices, where the hydrocarbon evaporates leaving the oil coating behind. There are a lot of uses for this solvent in households. Hinges and joints can be loosened as well as lubricated using this solvent which will help in cleaning out dirt and residue from bolts and screws that are jammed. By cleaning up the dirt and lubricating them, the corrosion of these hinges and bolts is kept at bay. As per the data sheet, the formula seemingly consists of a light lubricating oil, some inert components, and liquefied petroleum gas. It is a petroleum product although some people believe it really consists of fish oil. WD-40 also has carbon dioxide instead of LPG these days to avoid flammability.