Thread Calculator
Find minor diameter and thread depth from major diameter and TPI.
Find the minor diameter and thread depth for a UNC/UNF thread.
The math behind it
pitch = 1 ÷ TPI; depth = 0.6495 × pitch; minor diameter = major − 1.299 × pitch.
Worked example
½"-13 UNC → minor ~0.404 in.
FAQ
Metric?
Use the Thread Pitch calculator — in metric the pitch is given directly in mm.