What does WD-40 stand for?
WD-40 was developed in 1953 by Norman Larsen, founder of the Rocket Chemical Company, in San Diego, California. Having become available to consumers in 1958, it is still popular and widely used worldwide. The spray was originally designed for Convair to protect the outer skin of the Atlas Missile from rust and corrosion. Later the spray turned out to be very useful in household, which made it popular at the market.
The name of the spray is abbreviated from 'Water Displacement, 40th formula', which means the formula was perfected only on Larsen's 40th try.