Thread Calculator

Find minor diameter and thread depth from major diameter and TPI.

Minor diameter 0.9001
Thread depth 0.05

Formula: pitch = 1/TPI ; depth = 0.6495 × pitch ; minor = major − 1.299 × pitch

Step-by-step with your numbers:
1. Values used:
2. Major (nominal) diameter = 1
3. Threads per inch = 13 TPI
4.
5. Minor diameter = 0.9001
6. Thread depth = 0.05
Did we solve your problem today?

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.