3/4-6 ACME Thread Dimensions

Basic information

Designation

3/4-6 ACME

Thread system

ACME

Series

acme

Standard

ASME B1.5

Basic profile

ACME basic profile

Flank angle

29°

Dimensions

Major diameter

0.75 in / 19.05 mm

Pitch (metric equivalent)

4.233 mm

Threads per inch

6

Pitch diameter

0.6665 in / 16.93 mm

Minor diameter (external)

0.5634 in / 14.31 mm

Minor diameter (internal)

0.5634 in / 14.31 mm

Thread depth

0.0933 in / 2.371 mm

Recommended tap drill

Ø 0.5833 in / 14.817 mm

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.

No specification in this database uses 3/4-6 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.

Neighbouring sizes in ACME.