Work out thread pitch instantly with clear inputs, formula shown and shareable results.
Pitch is the axial distance between adjacent thread crests and is simply the reciprocal of threads per inch. For a 60 degree unified thread the basic minor diameter is the major diameter less 1.299 times the pitch, which is the figure behind tap drill selection.
Pitch
Pitch in = 1 / threads per inch; mm = pitch x 25.4
Minor diameter
Basic minor = major - 1.299 x pitch
Pitch in = 1 / threads per inch; mm = pitch x 25.4. Pitch is the axial distance between adjacent thread crests and is simply the reciprocal of threads per inch.
Fine threads have slightly more tensile area and resist loosening better under vibration, but coarse threads tolerate damage and coatings far better and are less likely to cross-thread.
This calculator takes 3 inputs: Threads per inch, Measured thread length, Major diameter. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.