METRICcoarse60° flankISO 261

M3 × 0.5 Thread Dimensions

M3 x 0.5 is a coarse ISO Metric thread. Pitch is 0.5 mm, equivalent to 50.8 threads per inch. The recommended tap drill is nominal diameter minus pitch.

Major Ø3 mm
Pitch0.5 mm
Threads per inch50.8
Pitch Ø2.68 mm
Tap drill2.5 mm

Thread profile

millimetres unless stated
Thread profile — M3 x 0.5d 3d2 2.68d3 2.39mm60°P 0.5h3 0.307tap ⌀2.5
M3 × 0.5 — basic profile60° flank angle · Not to scale

Basic information

Designation
M3 x 0.5
Thread system
ISO Metric
Series
coarse
Standard
ISO 261
Basic profile
ISO 68-1 basic profile
Flank angle
60°

Dimensions

Major diameter
3 mm
Pitch
0.5 mm
Threads per inch
50.8
Pitch diameter
2.68 mm
Minor diameter (external)
2.39 mm
Minor diameter (internal)
2.46 mm
Thread depth
0.307 mm
Recommended tap drill
Ø 2.5 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 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 parts166 specification pages

All M3 fasteners

Every fastener below is threaded M3 × 0.5, so a nut, bolt or washer picked from this list will mate with it.

DIN 912ISO 4762DIN 7991ISO 10642ISO 7380DIN 7984DIN 934ISO 4032DIN 985ISO 10511DIN 916DIN 914DIN 915DIN 913ISO 4029ISO 4027ISO 4028ISO 4026DIN 84ISO 1207DIN 85ISO 1580DIN 963ISO 2009
SpecificationLength
DIN 912 M3 × 5 Hexagon Socket Head Cap Screw5 mm
DIN 912 M3 × 6 Hexagon Socket Head Cap Screw6 mm
DIN 912 M3 × 8 Hexagon Socket Head Cap Screw8 mm
DIN 912 M3 × 10 Hexagon Socket Head Cap Screw10 mm
DIN 912 M3 × 12 Hexagon Socket Head Cap Screw12 mm
DIN 912 M3 × 16 Hexagon Socket Head Cap Screw16 mm
DIN 912 M3 × 20 Hexagon Socket Head Cap Screw20 mm
DIN 912 M3 × 25 Hexagon Socket Head Cap Screw25 mm
DIN 912 M3 × 30 Hexagon Socket Head Cap Screw30 mm
ISO 4762 M3 × 5 Hexagon Socket Head Cap Screw5 mm
ISO 4762 M3 × 6 Hexagon Socket Head Cap Screw6 mm
ISO 4762 M3 × 8 Hexagon Socket Head Cap Screw8 mm
ISO 4762 M3 × 10 Hexagon Socket Head Cap Screw10 mm
ISO 4762 M3 × 12 Hexagon Socket Head Cap Screw12 mm
ISO 4762 M3 × 16 Hexagon Socket Head Cap Screw16 mm
ISO 4762 M3 × 20 Hexagon Socket Head Cap Screw20 mm
ISO 4762 M3 × 25 Hexagon Socket Head Cap Screw25 mm
ISO 4762 M3 × 30 Hexagon Socket Head Cap Screw30 mm
DIN 7991 M3 × 6 Hexagon Socket Countersunk Head Screw6 mm
DIN 7991 M3 × 8 Hexagon Socket Countersunk Head Screw8 mm
DIN 7991 M3 × 10 Hexagon Socket Countersunk Head Screw10 mm
DIN 7991 M3 × 12 Hexagon Socket Countersunk Head Screw12 mm
DIN 7991 M3 × 16 Hexagon Socket Countersunk Head Screw16 mm
DIN 7991 M3 × 20 Hexagon Socket Countersunk Head Screw20 mm
DIN 7991 M3 × 25 Hexagon Socket Countersunk Head Screw25 mm
DIN 7991 M3 × 30 Hexagon Socket Countersunk Head Screw30 mm
ISO 10642 M3 × 6 Hexagon Socket Countersunk Head Screw6 mm
ISO 10642 M3 × 8 Hexagon Socket Countersunk Head Screw8 mm
ISO 10642 M3 × 10 Hexagon Socket Countersunk Head Screw10 mm
ISO 10642 M3 × 12 Hexagon Socket Countersunk Head Screw12 mm
ISO 10642 M3 × 16 Hexagon Socket Countersunk Head Screw16 mm
ISO 10642 M3 × 20 Hexagon Socket Countersunk Head Screw20 mm
ISO 10642 M3 × 25 Hexagon Socket Countersunk Head Screw25 mm
ISO 10642 M3 × 30 Hexagon Socket Countersunk Head Screw30 mm
ISO 7380 M3 × 6 Hexagon Socket Button Head Screw6 mm
ISO 7380 M3 × 8 Hexagon Socket Button Head Screw8 mm
ISO 7380 M3 × 10 Hexagon Socket Button Head Screw10 mm
ISO 7380 M3 × 12 Hexagon Socket Button Head Screw12 mm
ISO 7380 M3 × 16 Hexagon Socket Button Head Screw16 mm
ISO 7380 M3 × 20 Hexagon Socket Button Head Screw20 mm

Showing the first 40 of 166 specification pages.

Related

Other pitches at the same 3 mm diameter — a fine pitch on a coarse diameter, or the reverse, is the usual substitution question.

M3 × 0.35 fine

Neighbouring sizes in ISO Metric.

M2 × 0.25 fineM2.2 × 0.45M2.5 × 0.45M2.5 × 0.35 fineM3 × 0.35 fineM3.5 × 0.6M3.5 × 0.35 fineM4 × 0.7