WD-40 is a penetrating oil composed primarily of mineral spirits, aliphatic hydrocarbons, and aromatic hydrocarbons. Mineral spirits act as a lubricant, while aliphatic hydrocarbons and aromatic hydrocarbons serve as solvents for dissolving rust and breaking down deposits. The precise combination and proportions of these ingredients remain a trade secret, contributing to WD-40’s unique performance as a lubricant, rust preventative, and water displacer.
