UNCcoarse60° flankASME B1.1

3/4-10 UNC Thread Dimensions

3/4-10 UNC is a 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 is nominal diameter minus pitch.

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 has a fundamental triangle height H = 0.866025 × P, with pitch diameter d₂ = d − 0.649519 × P, external minor diameter d₃ = d − 1.226869 × P and internal minor diameter D₁ = d − 1.082532 × P; the two minor diameters differ because the external root is rounded while the internal crest is truncated. 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 Series2 in
ASME B18.2.1 3/4-10 × 2.5 Hex Head Cap Screw — Inch Series2.5 in
ASME B18.2.1 3/4-10 × 3 Hex Head Cap Screw — Inch Series3 in
ASME B18.2.1 3/4-10 × 4 Hex Head Cap Screw — Inch Series4 in
ASME B18.2.1 3/4-10 × 5 Hex Head Cap Screw — Inch Series5 in
ASME B18.2.1 3/4-10 × 6 Hex Head Cap Screw — Inch Series6 in
ASME B18.2.1 3/4-10 × 8 Hex Head Cap Screw — Inch Series8 in
ASME B18.3 3/4-10 × 2 Socket Head Cap Screw — Inch Series2 in
ASME B18.3 3/4-10 × 2.5 Socket Head Cap Screw — Inch Series2.5 in
ASME B18.3 3/4-10 × 3 Socket Head Cap Screw — Inch Series3 in
ASME B18.3 3/4-10 × 4 Socket Head Cap Screw — Inch Series4 in
ASME B18.3 3/4-10 × 5 Socket Head Cap Screw — Inch Series5 in
ASME B18.3 3/4-10 × 6 Socket Head Cap Screw — Inch Series6 in
ASME B18.2.2 3/4-10 Hex Nut — Inch Series—

The dash in the Length column marks a nut or a washer: those parts have no length to quote, so the dash means not applicable rather than missing data.

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