UNF Unified Fine Thread · ANSI/ASME B1.1

7/16" - 20 UNF Thread: Pitch, Tap Drill & Dimensions

7/16" - 20 UNF is a UNF Unified Fine Thread (ANSI/ASME B1.1) size, with a major diameter of 11.112 mm, 20 threads per inch (1.270 mm pitch). The tap drill is 9.90 mm.

Profile shape (schematic, not to scale)
7/16" - 20 UNF thread dimensions
Major Diameter (inch)0.438
Major Diameter (mm)11.112
Tapping Drill Size (mm)9.90
TPI20
Pitch (mm)1.270
Flank angle60°

Common questions

What size drill do I use to tap 7/16" - 20 UNF?

Use a 9.90 drill. This is the standard tap drill for 7/16" - 20 UNF; for hard materials or deep threads a slightly larger drill reduces tapping torque.

What is the pitch of 7/16" - 20 UNF?

The pitch of 7/16" - 20 UNF is 1.270, meaning the thread advances that distance in one full turn.

Where can I find other UNF Unified Fine Thread sizes?

The full UNF Unified Fine Thread table, with every size and a live filter, is on its standard page, and the Thread Finder searches all 73 standards at once.

Reference values; computed values use the ISO basic profile. Verify against the current standard before production use.

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