A screw thread in conformity with this International Standard is designated by the letter M followed by the values of the nominal diameter and of the pitch expressed in millimeters separated by the sign x.

Example : M 8 x 1.0 (Fine pitch 1.0)

The absence of the indication of pitch means that the coarse pitch is specified.

Example : M 8 (Coarse pitch 1.25)

The words “coarse” and “fine” are given in order to conform to usage. No concept of quality however, is associated with these words. “Coarse” pitches are the largest metric pitches used. For the diameter selected, choose one of the pitches shown on the corresponding line.

Basic Major Diameter Nominal Diameter (mm) STD Pitch in mm
Inch mm Coarse Fine M Taper
.0118 0.30 0.30 X 0.075
.0118 0.30 0.30 * 0.080
.0138 0.35 0.35 ** 0.090
.0146 0.37
.0157 0.40 0.40 *X 0.100
.0165 0.42
.0177 0.45 0.45 ** 0.100
.0189 0.48
.0197 0.50 0.50 *X 0.125
.0209 0.53
.0213 0.54
.0217 0.55 0.55 ** 0.125
.0236 0.60 0.60 *X 0.150
.0244 0.62
.0276 0.70 0.70 0.175
.0311 0.79
.0315 0.80 0.80 *X 0.200
.0340 0.86
.0354 0.90 0.90 **X 0.225
.0394 1.00 1.00 *X 0.250 0.2
.0433 1.10 1.10 ** 0.250 0.2
.0470 1.19
.0472 1.20 1.20 *X 0.250 0.2
.0512 1.30
.0551 1.40 1.40 **X 0.300 0.2
.0591 1.50 1.50 0.300
.0600 1.52
.0629 1.60 1.60 * 0.350 0.2
.0669 1.70 1.70 X 0.350 0.2,0.25
.0709 1.80 1.80 ** 0.350 0.2
.0730 1.85
.0748 1.90
.0787 2.00 2.00 *X 0.400 0.25,0.35
.0860 2.18
.0866 2.20 2.20 ** 0.450 0.25
.0906 2.30 2.30 X 0.400 0.25,0.35
.0984 2.50 2.50 * 0.45 0.35
.0990 2.51
.1024 2.60 2.60 X 0.45 0.25,0.35
.1102 2.80
.1120 2.84
.1181 3.00 3.00 *X 0.50 0.35
.1250 3.18
.1260 3.20
.1380 3.50 3.50 **X 0.60 0.35,0.5
.1417 3.60
.1575 4.00 4.00 *X 0.70 0.5,0.75
.1614 4.10
.1640 4.17
.1772 4.50 4.50 ** 0.75 0.5
.1850 4.70
.1875 4.76
.1900 4.83
.1969 5.00 5.00 *X 0.80 0.5, 0.75, 0.90
.2087 5.30
.2160 5.49
.2165 5.50 5.50 *** 0.90 0.5
.2188 5.56
.2362 6.00 6.00 *X 1.00 0.5, 0.75
.2500 6.35
.2756 7.00 7.00 ***X 1.00 0.5, 0.75
.2812 7.14
.3125 7.94
.3125 7.94
.3150 8.00 8.00 *X 1.25 0.5, 0.75, 1
.3543 9.00 9.00 ***X 1.25 0.75, 1
.3750 9.53
.3830 9.73 1
.3937 10.00 10.00 *X 1.5 0.75, 1, 1.25
.4050 10.29
.4331 11.00 11.00 ***X 1.5 0.75, 1, 1.25
.4375 11.11
.4724 12.00 12.00 *X 1.75 1, 1.25, 1.5 1.5
.5000 12.70
.5180 13.16
.5400 13.72
.5512 14.00 14.00 **X 2.00 1, 1.25, 1.5
.5625 14.29
.6250 15.88
.6299 16.00 16.00 *X 2.00 1, 1.5 1.5
.6560 16.66
.6750 17.15
.6875 17.46
.7087 18.00 18.00 **X 2.5 1, 1.5, 2 1.5
.7500 19.05
.7874 20.00 20 *X 2.5 1, 1.5, 2 1.5
.8125 20.64
.8250 20.96
.8400 21.34
.8661 22.00 22 **X 2.5 1, 1.5, 2 1.5
.8750 22.23
.9020 22.91
.9375 23.81
.9449 24.00 24 *X 3 1, 1.5, 2
1.0000 25.40
1.0236 26.00 26 ***X 1.5 1.5
1.041011 26.44
1.0500 26.67
1.0625 26.99
1.0630 27.00 27 **X 3 1, 1.5, 2
1.1250 28.58
1.1811 30.00 30 *X 3.5 1, 1.5, 2, 3
1.1875 30.16
1.1890 30.20
1.2500 31.75
1.2598 32.00 32 ***X 1.5, 2
1.2992 33.00 33 **X 3.5 1.5, 2, 3
1.3090 33.25
1.3125 33.34
1.3150 33.40
1.3750 34.93
1.3780 35.00 35 ***X 1.5
1.4173 36.00 36 *X 4 1.5, 2, 3
1.4375 36.51
1.4920 37.90 1.5
1.4961 38.00 38 ***X
1.5000 38.10
1.5354 39.00 39 **X 4 1.5, 2, 3
1.5625 39.69
1.5748 40.00 40 ***X 1.5, 2, 3
1.6250 41.28
1.6500 41.91
1.6535 42.00 42 *X 4.5 1.5, 2, 3, 4
1.6600 42.16
1.6875 42.86
1.7450 44.32
* ISO Standard-1st Choice
** ISO Standard-2nd Choice
*** ISO Standard-3rd Choice
X DIN (German Standard)
*All information is strictly informative
X