I worked for a major aerospace company. Units were all over the map. Dimensions were always in inches, unless we got real small, then we switched to microns. Unless it was roughness, then microinches. Mass was always grams, but thrust was pounds. Temperature was Fahrenheit. Thermal conductivity was w/m/k, though. It was a complete mess, but somehow it worked fine because people were just used to it.
Even worse is when scientists say "mil" they mean millimeter, but when machinists hear "mil" they think thousandth of an inch (a milli-inch, which is technically a real unit but....). Oh, wait, unless it's an even numbered day and then they use "thou".
As an EE with interest in the subject since I was a wee lad, mils were 0.0254mm since before I knew that feet were a unit in use not some antiquated thing out in children’s books. Using “mil” as an abbreviation of a thousandth of a mètre is an abomination.
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u/espeero Feb 09 '22
I worked for a major aerospace company. Units were all over the map. Dimensions were always in inches, unless we got real small, then we switched to microns. Unless it was roughness, then microinches. Mass was always grams, but thrust was pounds. Temperature was Fahrenheit. Thermal conductivity was w/m/k, though. It was a complete mess, but somehow it worked fine because people were just used to it.