Maybe its just the wingnut turning the spanner??? In the military for tactical aviation all work is documented in the log book or maintenance forms. A common term is R squared, (R2) which stands for Removed & Replace.
On occasion the pilots will make a mistake and write up a maintenance problem or fault to try to cover up the actual problem. Nothing is more difficult to replicate is a intermittent or non existent fault in order to ID the repair needed. Sometimes after extensive testing we have to document that fault not found.
No longer allowed but for a while my supervisor would write them up as.....
"Issue not verifiable, no defects found, R2 Stick actuator".
But all parts are made to a tolerance, In manufacturing you make it to the print and customer specs, call outs, and accepted deviations all need to be documented especially for parts made for medical, Military, transportation or Aerospace. My wife currently is Master scheduler as well of Goddess of expediting. Worked most every position in the company. Known as the old world term of
"Screw machine shop" Threaded parts are only part of the equation. The engineering staff can explain it better, but threads have a classification for fit & finish, and the metal surfaces have specs for finish as well.
If you would like a quote for a run of specialized parts or fasteners they do small runs. (Small runs are usually several thousand pieces but everything is graded to scale.) Brass, Steel, aluminum, stainless and whatever surface finishes you want, plating, anodizing, or heat treat...
See:
http://www.enochmachining.com/
