Construction

Thread Calculator

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

Calculated Output

Minor diameter 0.9001

Thread depth 0.05

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

Step-by-Step Breakdown

1. Values used:

2. Major (nominal) diameter = 1

3. Threads per inch = 13 TPI

5. Minor diameter = 0.9001

6. Thread depth = 0.05

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The math behind it

pitch = 1 ÷ TPI; depth = 0.6495 × pitch; minor diameter = major − 1.299 × pitch.

½"-13 UNC → minor ~0.404 in.

Metric?

Use the Thread Pitch calculator — in metric the pitch is given directly in mm.