UNFfine60° flankASME B1.1

#0-80 UNF Thread Dimensions

#0-80 UNF is a fine Unified National Fine thread. There are 80 threads per inch on a 0.0598 in major diameter, giving a metric-equivalent pitch of 0.318 mm. The recommended tap drill leaves roughly 75% thread engagement.

Major Ø0.0598 in

Threads per inch80

Pitch (metric)0.318 mm

Pitch Ø0.052 in

Tap drill0.0476 in

Thread profile

millimetres unless stated

#0-80 UNF — basic profile60° flank angle · Not to scale

Basic information

Designation: #0-80 UNF
Thread system: Unified National Fine
Series: fine
Standard: ASME B1.1
Basic profile: Unified basic profile
Flank angle: 60°

Dimensions

Major diameter: 0.0598 in / 1.52 mm
Pitch (metric equivalent): 0.318 mm
Threads per inch: 80
Pitch diameter: 0.052 in / 1.32 mm
Minor diameter (external): 0.0445 in / 1.13 mm
Minor diameter (internal): 0.0465 in / 1.18 mm
Thread depth: 0.0077 in / 0.195 mm
Recommended tap drill: Ø 0.0476 in / 1.21 mm

How these values are derived

computed from the basic profile

These figures follow the Unified basic profile of ASME B1.1. A 60° basic profile uses a fundamental triangle height H = 0.866025 × P, with external minor diameter d₃ = d − 1.226869 × P and internal minor diameter D₁ = d − 1.082532 × P; the two differ because the external root is rounded while the internal crest is truncated. A 55° Whitworth profile uses H = 0.960491 × P and a thread height of 0.640327 × P. The recommended tap drill is given as nominal diameter minus pitch, which approximates 75% thread engagement — adjust it for tough materials or deep holes.

Compatible parts0 specification pages

No specification in this database uses #0-80 UNF yet.

Neighbouring sizes in Unified National Fine.

#1-72 UNF #2-64 UNF #3-56 UNF #4-48 UNF