UNCcoarse60° flankASME B1.1

3/4-10 UNC Thread Dimensions

3/4-10 UNC is a coarse Unified National Coarse thread. There are 10 threads per inch on a 0.75 in major diameter, giving a metric-equivalent pitch of 2.54 mm. The recommended tap drill leaves roughly 75% thread engagement.

Major Ø0.75 in
Threads per inch10
Pitch (metric)2.54 mm
Pitch Ø0.685 in
Tap drill0.65 in

Thread profile

millimetres unless stated
Thread profile — 3/4-10 UNCd 19.05d2 17.4d3 15.93mm60°P 2.54h3 1.558tap ⌀16.51
3/4-10 UNC — basic profile60° flank angle · Not to scale

Basic information

Designation
3/4-10 UNC
Thread system
Unified National Coarse
Series
coarse
Standard
ASME B1.1
Basic profile
Unified basic profile
Flank angle
60°

Dimensions

Major diameter
0.75 in / 19.05 mm
Pitch (metric equivalent)
2.54 mm
Threads per inch
10
Pitch diameter
0.685 in / 17.4 mm
Minor diameter (external)
0.6272 in / 15.93 mm
Minor diameter (internal)
0.6417 in / 16.3 mm
Thread depth
0.0613 in / 1.558 mm
Recommended tap drill
Ø 0.65 in / 16.51 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 parts14 specification pages

All 3/4-10 fasteners

Every fastener below is threaded 3/4-10 UNC, so a nut, bolt or washer picked from this list will mate with it.

ASME B18.2.1ASME B18.3ASME B18.2.2
SpecificationLength
ASME B18.2.1 3/4-10 × 2 Hex Head Cap Screw — Inch Series0.0787 in
ASME B18.2.1 3/4-10 × 2.5 Hex Head Cap Screw — Inch Series0.0984 in
ASME B18.2.1 3/4-10 × 3 Hex Head Cap Screw — Inch Series0.1181 in
ASME B18.2.1 3/4-10 × 4 Hex Head Cap Screw — Inch Series0.1575 in
ASME B18.2.1 3/4-10 × 5 Hex Head Cap Screw — Inch Series0.1969 in
ASME B18.2.1 3/4-10 × 6 Hex Head Cap Screw — Inch Series0.2362 in
ASME B18.2.1 3/4-10 × 8 Hex Head Cap Screw — Inch Series0.315 in
ASME B18.3 3/4-10 × 2 Socket Head Cap Screw — Inch Series0.0787 in
ASME B18.3 3/4-10 × 2.5 Socket Head Cap Screw — Inch Series0.0984 in
ASME B18.3 3/4-10 × 3 Socket Head Cap Screw — Inch Series0.1181 in
ASME B18.3 3/4-10 × 4 Socket Head Cap Screw — Inch Series0.1575 in
ASME B18.3 3/4-10 × 5 Socket Head Cap Screw — Inch Series0.1969 in
ASME B18.3 3/4-10 × 6 Socket Head Cap Screw — Inch Series0.2362 in
ASME B18.2.2 3/4-10 Hex Nut — Inch Series—

Related

Neighbouring sizes in Unified National Coarse.

7/16-14 UNC1/2-13 UNC9/16-12 UNC5/8-11 UNC7/8-9 UNC1-8 UNC1-1/8-7 UNC1-1/4-7 UNC