METRICcoarse60° flankISO 261

M22 × 2.5 Thread Dimensions

M22 x 2.5 is a coarse ISO Metric thread. Pitch is 2.5 mm, equivalent to 10.16 threads per inch. The recommended tap drill leaves roughly 75% thread engagement.

Major Ø22 mm
Pitch2.5 mm
Threads per inch10.16
Pitch Ø20.38 mm
Tap drill19.5 mm

Thread profile

millimetres unless stated
Thread profile — M22 x 2.5d 22d2 20.38d3 18.93mm60°P 2.5h3 1.534tap ⌀19.5
M22 × 2.5 — basic profile60° flank angle · Not to scale

Basic information

Designation
M22 x 2.5
Thread system
ISO Metric
Series
coarse
Standard
ISO 261
Basic profile
ISO 68-1 basic profile
Flank angle
60°

Dimensions

Major diameter
22 mm
Pitch
2.5 mm
Threads per inch
10.16
Pitch diameter
20.38 mm
Minor diameter (external)
18.93 mm
Minor diameter (internal)
19.29 mm
Thread depth
1.534 mm
Recommended tap drill
Ø 19.5 mm

How these values are derived

computed from the basic profile

These figures follow the ISO 68-1 basic profile of ISO 261. 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

All M22 fasteners

No specification in this database uses M22 × 2.5 yet.

Related

Other pitches at the same 22 mm diameter — a fine pitch on a coarse diameter, or the reverse, is the usual substitution question.

Neighbouring sizes in ISO Metric.