(This post was last modified: 04-30-2020, 12:58 PM by DanLaw.)
I If he is a machinist, can send you thread guides to determine appropriate threading.
There are 2 metrics: diametre of the fastener and spacing of the threads.
For motorsports usage specing machining or determining an unknown torque value, will make an assessment of thread diametre/pitch using thread checkers as it quick, easy and accurate. Prefer the MSC checkers arrayed on a wire:
Or these cards of various sizes:
The best amongst us will employ a Mitutoyo Thread Guage:
Or for the MIT/CMU grads:
While possessing all these, find the mechanical thread checkers arrayed on a wire or plate the quickest and more than adequately reliable.
One could choose to go to a local Home Depot or Lowes, toting the pieces to avail self of the fastener arrays they have in their fastener ailes if too parsimonious to spend the money on any of the gauges suggested - but truth told, every home should have some method to check common fastener sizes. Experience indicates 5x0,8 metric the new standard but likely NOT universal. Under NO circumstances is mixing metric with SAE or Screw Pitch EVER recommended and WILL end in tears - GUARANTEED.
Home handymen need wrap their head around the fact that fasteners are not of same philosophy where imprecision and covering with paint suffice. Am constantly frustrated at the atrocious quality of construction and repair that goes into most families’ single biggest lifetime investment. If I prepared cars as homes are built, virtually every one of my clients would die; same can even be stated of auto manufacturers: if they built autos as homes are built, millions of people would die on a daily basis - it cuts to the heart of character and being a man....