"certified' parts

Some parts, like Timken tapered roller wheel bearings, carry the same
part number as the industrial bearings, but the Quality Testing as the
factory is different for the aviation bearings. They will test 1 out of
ten for aviation instead of 1 out of 500 for industry. The factory also
puts away a lot more money to cover their butts when we pilots act
stupid, crash an airplane, and our families sue everyone that had
anything at all to do with that airplane in the last 18 years.
Including Timken, who somehow was negligent because their bearing
allowed us to fly VFR in IMC.
In Canada, the government is working on a "Commercial
Equivalent" provision to allow us to use industrial stuff that carries
the same part number as the aviation version. In that case, I suppose,
we mechanics would carry the liability instead of the manufacturer and
vendors. It's always someone else's fault, see?

Dan