" Good one terry you pulled a fast one LOL, Spoke to lenny at RENNtech he told me that 2 liter Diesel would be great for upgrade, problem as USUAL is getting a Guinea PIg to come forward, hope you can get one Good luck amigo "
To the tenth is definitely not used in aerospace industry all the time outside of precision fit items. Usually to the thousandth, and we have trouble getting vendors to hold it to that on a regular basis. Shafts/blades/etc are built/measured to smaller tolerances but those are definitely precision fit items. Did you put an extra zero in, or, since your name is Aerotest, do you test a small selection of very precisely machined parts? I work on APU's mostly.
It depends where youre looking, but a quick look at my APUs here show splines, blades, shafts, pump components held to 0.0001 and greater, and tight tolerances for straightness and flatness. "