ACMEacme29° flankASME B1.5

1/2-10 ACME Thread Dimensions

1/2-10 ACME is an ACME thread. There are 10 threads per inch on a 0.5 in major diameter, giving a metric-equivalent pitch of 2.54 mm. The recommended tap drill is nominal diameter minus pitch.

Major Ø0.5 in
Threads per inch10
Pitch (metric)2.54 mm
Pitch Ø0.45 in
Tap drill0.4 in

Thread profile

millimetres unless stated
Thread profile — 1/2-10 ACMEd 12.7d2 11.43d3 9.65mm29°P 2.54h3 1.524tap ⌀10.16
1/2-10 ACME — basic profile29° flank angle · Not to scale

Basic information

Designation
1/2-10 ACME
Thread system
ACME
Series
acme
Standard
ASME B1.5
Basic profile
ACME basic profile
Flank angle
29°

Dimensions

Major diameter
0.5 in / 12.7 mm
Pitch (metric equivalent)
2.54 mm
Threads per inch
10
Pitch diameter
0.45 in / 11.43 mm
Minor diameter (external)
0.3799 in / 9.65 mm
Minor diameter (internal)
0.3799 in / 9.65 mm
Thread depth
0.06 in / 1.524 mm
Recommended tap drill
Ø 0.4 in / 10.16 mm

How these values are derived

computed from the basic profile

These figures follow the ACME basic profile of ASME B1.5. A 29° ACME profile has a thread height of h = 0.5 × P + 0.01 in, the 0.01 in being the ACME clearance rather than a rounding: the pitch diameter is d₂ = d − 0.5 × P, the external minor diameter is d₃ = d − 2h, and the internal minor diameter is D₁ = d − P − 0.02 in. The recommended tap drill is given as nominal diameter minus pitch, which here sits 0.02 in above the basic internal minor diameter — that 0.02 in is the ACME crest clearance — so it is a starting point rather than a cutting recommendation.

Compatible parts0 specification pages

No specification in this database uses 1/2-10 ACME. Power threads are not fastener threads — they are found on lead screws, jacks and vice screws, so no bolt or nut in this catalogue is made in this form. The geometry above is what a machinist needs to cut it.

Related

Neighbouring sizes in ACME.