UNC Unified Coarse Thread · ANSI/ASME B1.1

5/8" - 11 UNC Thread: Pitch, Tap Drill & Dimensions

5/8" - 11 UNC is a UNC Unified Coarse Thread (ANSI/ASME B1.1) size, with a major diameter of 15.875 mm, 11 threads per inch (2.309 mm pitch). The tap drill is 13.53 mm.

Profile shape (schematic, not to scale)
5/8" - 11 UNC thread dimensions
Major Diameter (inch)0.625
Major Diameter (mm)15.875
Tapping Drill Size (mm)13.53
TPI11
Pitch (mm)2.309
Flank angle60°

Common questions

What size drill do I use to tap 5/8" - 11 UNC?

Use a 13.53 drill. This is the standard tap drill for 5/8" - 11 UNC; for hard materials or deep threads a slightly larger drill reduces tapping torque.

What is the pitch of 5/8" - 11 UNC?

The pitch of 5/8" - 11 UNC is 2.309, meaning the thread advances that distance in one full turn.

Where can I find other UNC Unified Coarse Thread sizes?

The full UNC Unified Coarse 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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