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ISO metric thread database

Type a designation, get every dimension.

M, MJ, and Tr -- basic dimensions computed from ISO 724/2904, plus ISO 965-1 pitch diameter tolerance limits for a class like 6g or 6H. Metric threads are identified by pitch (the millimeter distance between crests), not threads per inch, so start by typing the designation exactly as it appears on the print.

MØ12 mmP 1.5 mm6g

Small allowance -- the common general-purpose external class.

Try “M12x1.5-6g”, “M8” (coarse pitch assumed), “MJ6-4h6h”, or “Tr20x4-8H”. Add “-LH” for a left-hand thread.

Calculated live

Pitch diameter limits10.859 mm – 10.994 mmBasic 11.026 mm, allowance -0.032 mm

Basic dimensions

Major diameter
12.000 mm
Pitch diameter
11.026 mm
Minor diameter
10.376 mm

Major diameter (crest)

Maximum
11.969 mm
Minimum
per ISO 965-1 tables

Tap drill · 75% thread

Tap drill
10.75 mm (10.782 mm calculated)
Clearance drill (normal)
12.75 mm (12.800 mm calculated)
M· ISO General Purpose

The standard 60 degree thread used globally for fasteners. Coarse pitch is the default; fine pitch requires stating the pitch explicitly.

MJ· Aerospace / High-Fatigue

Shares the 60 degree M profile but adds a strictly controlled, enlarged root radius to resist stress fractures under cyclic load.

Tr· Trapezoidal

The metric equivalent of Acme threads: a 30 degree thread angle for lead screws and heavy power transmission, not fastening.

M· ISO General Purpose

ISO General Purpose (ISO 261 / ISO 724)

53 sizes

Coarse pitch (default)

M1

P 0.25 mm

M1.2

P 0.25 mm

M1.6

P 0.35 mm

M2

P 0.4 mm

M2.5

P 0.45 mm

M3

P 0.5 mm

M3.5

P 0.6 mm

M4

P 0.7 mm

M5

P 0.8 mm

M6

P 1 mm

M7

P 1 mm

M8

P 1.25 mm

M10

P 1.5 mm

M12

P 1.75 mm

M14

P 2 mm

M16

P 2 mm

M18

P 2.5 mm

M20

P 2.5 mm

M22

P 2.5 mm

M24

P 3 mm

M27

P 3 mm

M30

P 3.5 mm

M33

P 3.5 mm

M36

P 4 mm

M39

P 4 mm

M42

P 4.5 mm

M45

P 4.5 mm

M48

P 5 mm

M52

P 5 mm

M56

P 5.5 mm

M60

P 5.5 mm

M64

P 6 mm

Fine pitch (pitch stated explicitly)

M8 x 1

P 1 mm

M10 x 1.25

P 1.25 mm

M12 x 1.25

P 1.25 mm

M14 x 1.5

P 1.5 mm

M16 x 1.5

P 1.5 mm

M18 x 1.5

P 1.5 mm

M20 x 1.5

P 1.5 mm

M22 x 1.5

P 1.5 mm

M24 x 2

P 2 mm

M27 x 2

P 2 mm

M30 x 2

P 2 mm

M33 x 2

P 2 mm

M36 x 3

P 3 mm

M39 x 3

P 3 mm

M42 x 3

P 3 mm

M45 x 3

P 3 mm

M48 x 3

P 3 mm

M52 x 4

P 4 mm

M56 x 4

P 4 mm

M60 x 4

P 4 mm

M64 x 4

P 4 mm

MJ· Aerospace / High-Fatigue

Aerospace / High-Fatigue (ISO 5855 / MIL-S-8879)

34 sizes

Coarse pitch

MJ1.6

P 0.35 mm

MJ2

P 0.4 mm

MJ2.5

P 0.45 mm

MJ3

P 0.5 mm

MJ3.5

P 0.6 mm

MJ4

P 0.7 mm

MJ5

P 0.8 mm

MJ6

P 1 mm

MJ8

P 1.25 mm

MJ10

P 1.5 mm

MJ12

P 1.75 mm

MJ14

P 2 mm

MJ16

P 2 mm

MJ18

P 2.5 mm

MJ20

P 2.5 mm

MJ22

P 2.5 mm

MJ24

P 3 mm

MJ27

P 3 mm

MJ30

P 3.5 mm

MJ33

P 3.5 mm

MJ36

P 4 mm

Fine pitch

MJ8 x 1

P 1 mm

MJ10 x 1.25

P 1.25 mm

MJ12 x 1.25

P 1.25 mm

MJ14 x 1.5

P 1.5 mm

MJ16 x 1.5

P 1.5 mm

MJ18 x 1.5

P 1.5 mm

MJ20 x 1.5

P 1.5 mm

MJ22 x 1.5

P 1.5 mm

MJ24 x 2

P 2 mm

MJ27 x 2

P 2 mm

MJ30 x 2

P 2 mm

MJ33 x 2

P 2 mm

MJ36 x 3

P 3 mm

Tr· Trapezoidal

Trapezoidal (ISO 2904 / DIN 103)

24 sizes

Tr8 x 1.5

P 1.5 mm

Tr9 x 2

P 2 mm

Tr10 x 2

P 2 mm

Tr11 x 2

P 2 mm

Tr12 x 3

P 3 mm

Tr14 x 3

P 3 mm

Tr16 x 4

P 4 mm

Tr18 x 4

P 4 mm

Tr20 x 4

P 4 mm

Tr22 x 5

P 5 mm

Tr24 x 5

P 5 mm

Tr26 x 5

P 5 mm

Tr28 x 5

P 5 mm

Tr30 x 6

P 6 mm

Tr32 x 6

P 6 mm

Tr34 x 6

P 6 mm

Tr36 x 6

P 6 mm

Tr38 x 7

P 7 mm

Tr40 x 7

P 7 mm

Tr42 x 7

P 7 mm

Tr44 x 7

P 7 mm

Tr46 x 8

P 8 mm

Tr48 x 8

P 8 mm

Tr50 x 8

P 8 mm

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