METRICcoarse60° flankISO 261

M11 × 1.5 Thread Dimensions

M11 x 1.5 is a coarse ISO Metric thread. Pitch is 1.5 mm, equivalent to 16.93 threads per inch. The recommended tap drill leaves roughly 75% thread engagement.

Major Ø11 mm
Pitch1.5 mm
Threads per inch16.93
Pitch Ø10.03 mm
Tap drill9.5 mm

Thread profile

millimetres unless stated
Thread profile — M11 x 1.5d 11d2 10.03d3 9.16mm60°P 1.5h3 0.92tap ⌀9.5
M11 × 1.5 — basic profile60° flank angle · Not to scale

Basic information

Designation
M11 x 1.5
Thread system
ISO Metric
Series
coarse
Standard
ISO 261
Basic profile
ISO 68-1 basic profile
Flank angle
60°

Dimensions

Major diameter
11 mm
Pitch
1.5 mm
Threads per inch
16.93
Pitch diameter
10.03 mm
Minor diameter (external)
9.16 mm
Minor diameter (internal)
9.38 mm
Thread depth
0.92 mm
Recommended tap drill
Ø 9.5 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

No specification in this database uses M11 × 1.5 yet.

Related

Other pitches at the same 11 mm diameter — a fine pitch on a coarse diameter, or the reverse, is the usual substitution question.

Neighbouring sizes in ISO Metric.