METRICfine60° flankISO 262

M2.5 × 0.35 fine Thread Dimensions

M2.5 x 0.35 (fine) is a fine ISO Metric thread. Pitch is 0.35 mm, equivalent to 72.57 threads per inch. The recommended tap drill is nominal diameter minus pitch.

Major Ø2.5 mm

Pitch0.35 mm

Threads per inch72.57

Pitch Ø2.27 mm

Tap drill2.15 mm

Thread profile

millimetres unless stated

M2.5 × 0.35 fine — basic profile60° flank angle · Not to scale

Basic information

Designation: M2.5 x 0.35 (fine)
Thread system: ISO Metric
Series: fine
Standard: ISO 262
Basic profile: ISO 68-1 basic profile
Flank angle: 60°

Dimensions

Major diameter: 2.5 mm
Pitch: 0.35 mm
Threads per inch: 72.57
Pitch diameter: 2.27 mm
Minor diameter (external): 2.07 mm
Minor diameter (internal): 2.12 mm
Thread depth: 0.215 mm
Recommended tap drill: Ø 2.15 mm

How these values are derived

computed from the basic profile

These figures follow the ISO 68-1 basic profile of ISO 262. 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 parts0 specification pages

No specification in this database uses M2.5 × 0.35 fine yet.

Other pitches at the same 2.5 mm diameter — a fine pitch on a coarse diameter, or the reverse, is the usual substitution question.

M2.5 × 0.45

Neighbouring sizes in ISO Metric.

M2 × 0.4 M2 × 0.25 fine M2.2 × 0.45 M2.5 × 0.45 M3 × 0.5 M3 × 0.35 fine M3.5 × 0.6 M3.5 × 0.35 fine