The History of WD-40
disclosure: I work in automotive trade craft as a diesel mechanic and I dont care to have WD40 in my shop at all for a few reasons:0. It is a solvent, not a lubricant.  This is often lost on apprentices until they wear out a drive chain or blow up a firearm.  WD40 does a terrible job of blurring that line.  even the article touts it several times as a lubricant :(1.  it absolutely CAN NOT be used around hot work, unlike most other lubricants like ND999.  cans --aerosol or not-- are treated just like a can of petrol.2.  Again, it is stunningly flammable both in and out of its aerosol form because its mostly kerosene.  That means aerosol vapors floating around a powdercoat setup, an open flame, or any ignition spark, will cause it to catch fire.  if your apprentice just hosed down a part with WD40 and you need to take a torch to it, youre going to have a bad time.https://en.wikipedia.org/wiki/WD-40