Originally Posted by Amos
WD-40 stands for Water Displacement #40 it was originally meant to displace water off of electrical things... at least that is what I've been told.
I remember my chemistry prof in college telling me about this. You're correct on the name. As the name states, it was originally developed to prevent corrosion on metal parts by displacing the water. And they got it right on the 40th attempt, hence the WD-40 name. Its original use was to prevent corrosion and icing on Atlas missiles.