If you're going to do Imperial machining, definitely use 10 TPI or 20 TPI. Why? Do the math.
For each turn of the screw, the nut moves 0.100" for a 10 TPI. For a 20TPI, the motion is 0.050" per rev.
It is a lot easier to do the math (in head or on paper) than with the 0.166666666"/rev of the 6 TPI or some other odd ball thread unless it is 8 TPI (0.125" per rev).
All the other explanations eventually pertain but this is why I'd pay to use 10 TPI or 20 TPI instead of a free anything else (unless it was 8 TPI, but only if I couldn't get 10 or 20)..... |