thumb|upright|WD-40 spray can from Germany

WD-40 (Water Displacement, 40th formula) is a penetrating oil manufactured by the WD-40 Company based in San Diego, California. Its formula was invented for the Rocket Chemical Company in 1953, and it became available as a commercial product in 1958. It acts as a lubricant, rust preventive, penetrant and moisture displacer. There are specialized products that perform better than WD-40 in many of these uses, but WD-40's flexibility has given it fame as a jack of all trades.

, WD-40 remains a very popular product. In 2014, it was inducted into the International Air & Space Hall of Fame at the San Diego Air & Space Museum.

History

Sources credit different people with inventing WD-40 formula in 1953 as part of the Rocket Chemical Company (later renamed to the WD-40 Company), in San Diego, California; the formula was kept as a trade secret and was never patented to avoid public disclosure of the ingredients. while the WD-40 company website and other books and newspapers credit Norman B. Larsen. According to Engstrand, "(Iver Norman) Lawson was acknowledged at the time, but his name later became confused with company president Norman B. Larsen." "WD-40" is abbreviated from the term "Water Displacement, 40th formula", suggesting it was the result of the 40th attempt to create the product. By 1965 it was being used by airlines including Delta and United; United, for example, was using it on fixed and movable joints of their DC-8 and Boeing 720s in maintenance and overhaul. At that time, airlines were using a variant called WD-60 to clean turbines, removing light rust from control lines, and when handling or storing metal parts. In 1973, WD-40 Company, Inc., went public with its first stock offering. Its NASDAQ stock symbol is ().

Formulation

WD-40's formula is a trade secret. The original copy of the formula was moved to a secure bank vault in San Diego in 2018. To avoid disclosing its composition, the product was not patented in 1953, and the window of opportunity for patenting it has long since closed.

WD-40's main ingredients as supplied in aerosol cans, according to the US material safety data sheet information, and with the CAS numbers interpreted:

  • 45–50% low vapor pressure aliphatic hydrocarbon (isoparaffin)
  • <35% petroleum base oil (non-hazardous heavy paraffins)
  • <25% aliphatic hydrocarbons (same CAS number as the first item, but flammable)
  • 2–3% carbon dioxide (propellant)

The European formulation is stated according to the REACH regulations:

  • 60–80% hydrocarbons C – C n-alkanes, iso-alkanes, cyclics <2% aromatics
  • 1–5% carbon dioxide

The Australian formulation is stated:

  • 50–60% naphtha (petroleum), hydrotreated heavy
  • <25% petroleum base oils
  • <10% naphtha (petroleum), hydrodesulfurized heavy (contains: 1,2,4-trimethyl benzene, 1,3,5-trimethyl benzene, xylene, mixed isomers)
  • 2–4% carbon dioxide

In 2009, Wired published an article with the results of gas chromatography and mass spectrometry tests on WD-40, showing that the principal components were C to C alkanes and mineral oil.

See also

  • Ballistol
  • CRC Industries

References

  • WD-40 Safety Data Sheets
  • WD-40 uses, by Snopes.com