Dimensions mm · values as the standard states them Size P dk m da t n mass M1 0.25 2.5
2.25 – 2.5
1
0.75 – 1
1 – 1.15
0.3 – 0.5
0.3
0.36 – 0.5
0.034
M1.2 0.25 3
2.75 – 3
1.2
0.95 – 1.2
1.2 – 1.4
0.4 – 0.6
0.4
0.46 – 0.6
0.057
M1.4 0.3 3
2.75 – 3
1.4
1.15 – 1.4
1.4 – 1.6
0.5 – 0.7
0.4
0.46 – 0.6
0.063
M1.6 0.35 3.5
3.2 – 3.5
1.6
1.35 – 1.6
1.6 – 1.84
0.6 – 0.8
0.5
0.56 – 0.7
0.1
M2 0.4 4.5
4.2 – 4.5
2
1.75 – 2
2 – 2.3
0.8 – 1
1
1.06 – 1.2
0.21
M2.5 0.45 4.5
4.2 – 4.5
2
1.75 – 2
2 – 2.3
0.8 – 1
1
1.06 – 1.2
0.21
M3 0.5 6
5.7 – 6
2.5
2.25 – 2.5
3 – 3.5
1 – 1.2
1.2
1.26 – 1.51
0.43
(M3.5) 0.6 7
6.64 – 7
3
2.75 – 3
3.45 – 4
1 – 1.4
1.4
1.46 – 1.71
0.7
M4 0.7 8
7.64 – 8
3.5
3.2 – 3.5
4 – 4.6
1.2 – 1.6
1.4
1.46 – 1.71
1.07
M5 0.8 9
8.64 – 9
4.2
3.9 – 4.2
5 – 5.75
1.5 – 1.9
2
2.06 – 2.31
1.8
M6 1 11
10.57 – 11
5
4.7 – 5
6 – 6.75
2 – 2.4
2.5
2.56 – 2.81
2.73
M8 1.25 14
13.57 – 14
6.5
6.14 – 6.5
8 – 8.75
2.5 – 3
3
3.06 – 3.31
5.57
M10 1.5 18
17.57 – 18
8
7.64 – 8
10 – 10.8
3.2 – 3.7
3.5
3.57 – 3.87
11.5
M12 1.75 21
20.48 – 21
10
9.64 – 10
12 – 13
3.8 – 4.3
4
4.07 – 4.37
21.5
(M14) 2 24
23.48 – 24
11
10.57 – 11
14 – 15.1
3.8 – 4.3
4
4.07 – 4.37
27.1
M16 2 26
25.48 – 26
12
11.57 – 12
16 – 17.3
3.8 – 4.3
4
4.07 – 4.37
36.8
(M18) 2.5 29
28.48 – 29
13
12.57 – 13
18 – 19.5
4.8 – 5.5
4
4.07 – 4.37
48.4
M20 2.5 32
31.38 – 32
14
13.57 – 14
20 – 21.6
4.8 – 5.5
5
5.07 – 5.37
57.2
Ranges read min – max; ≤ / ≥ where the standard gives one limit, ≈ for approximate values. Sizes in (brackets) are non-preferred. Select a row for its size sheet.
Size sheet · DIN 546
M1
dk external diameter of the nut 2.5
m nut height 1
da transition diameter 1 – 1.15
t groove depth 0.3 – 0.5
n groove width 0.3
mass mass per 1000 pieces (kg) 0.034 Thread · ISO 261/262
Pitch P 0.25
d2 0.838
d3 0.693
Tap drill 0.75
Stress area As 0.46 mm² Size sheet · DIN 546
M1.2
dk external diameter of the nut 3
m nut height 1.2
da transition diameter 1.2 – 1.4
t groove depth 0.4 – 0.6
n groove width 0.4
mass mass per 1000 pieces (kg) 0.057 Thread · ISO 261/262
Pitch P 0.25
d2 1.038
d3 0.893
Tap drill 0.95
Stress area As 0.73 mm² Size sheet · DIN 546
M1.4
dk external diameter of the nut 3
m nut height 1.4
da transition diameter 1.4 – 1.6
t groove depth 0.5 – 0.7
n groove width 0.4
mass mass per 1000 pieces (kg) 0.063 Thread · ISO 261/262
Pitch P 0.3
d2 1.205
d3 1.032
Tap drill 1.1
Stress area As 0.98 mm² Size sheet · DIN 546
M1.6
dk external diameter of the nut 3.5
m nut height 1.6
da transition diameter 1.6 – 1.84
t groove depth 0.6 – 0.8
n groove width 0.5
mass mass per 1000 pieces (kg) 0.1 Thread · ISO 261/262
Pitch P 0.35
d2 1.373
d3 1.171
Tap drill 1.25
Stress area As 1.27 mm² Size sheet · DIN 546
M2
dk external diameter of the nut 4.5
m nut height 2
da transition diameter 2 – 2.3
t groove depth 0.8 – 1
n groove width 1
mass mass per 1000 pieces (kg) 0.21 Thread · ISO 261/262
Pitch P 0.4
d2 1.74
d3 1.509
Tap drill 1.6
Stress area As 2.07 mm² Size sheet · DIN 546
M2.5
dk external diameter of the nut 4.5
m nut height 2
da transition diameter 2 – 2.3
t groove depth 0.8 – 1
n groove width 1
mass mass per 1000 pieces (kg) 0.21 Thread · ISO 261/262
Pitch P 0.45
d2 2.208
d3 1.948
Tap drill 2.05
Stress area As 3.39 mm² Size sheet · DIN 546
M3
dk external diameter of the nut 6
m nut height 2.5
da transition diameter 3 – 3.5
t groove depth 1 – 1.2
n groove width 1.2
mass mass per 1000 pieces (kg) 0.43 Thread · ISO 261/262
Pitch P 0.5
d2 2.675
d3 2.387
Tap drill 2.5
Stress area As 5.03 mm² Size sheet · DIN 546
M3.5
dk external diameter of the nut 7
m nut height 3
da transition diameter 3.45 – 4
t groove depth 1 – 1.4
n groove width 1.4
mass mass per 1000 pieces (kg) 0.7 Thread · ISO 261/262
Pitch P 0.6
d2 3.11
d3 2.764
Tap drill 2.9
Stress area As 6.78 mm² Size sheet · DIN 546
M4
dk external diameter of the nut 8
m nut height 3.5
da transition diameter 4 – 4.6
t groove depth 1.2 – 1.6
n groove width 1.4
mass mass per 1000 pieces (kg) 1.07 Thread · ISO 261/262
Pitch P 0.7
d2 3.545
d3 3.141
Tap drill 3.3
Stress area As 8.78 mm² Size sheet · DIN 546
M5
dk external diameter of the nut 9
m nut height 4.2
da transition diameter 5 – 5.75
t groove depth 1.5 – 1.9
n groove width 2
mass mass per 1000 pieces (kg) 1.8 Thread · ISO 261/262
Pitch P 0.8
d2 4.48
d3 4.019
Tap drill 4.2
Stress area As 14.18 mm² Size sheet · DIN 546
M6
dk external diameter of the nut 11
m nut height 5
da transition diameter 6 – 6.75
t groove depth 2 – 2.4
n groove width 2.5
mass mass per 1000 pieces (kg) 2.73 Thread · ISO 261/262
Pitch P 1
d2 5.35
d3 4.773
Tap drill 5
Stress area As 20.12 mm² Size sheet · DIN 546
M8
dk external diameter of the nut 14
m nut height 6.5
da transition diameter 8 – 8.75
t groove depth 2.5 – 3
n groove width 3
mass mass per 1000 pieces (kg) 5.57 Thread · ISO 261/262
Pitch P 1.25
d2 7.188
d3 6.466
Tap drill 6.75
Stress area As 36.61 mm² Size sheet · DIN 546
M10
dk external diameter of the nut 18
m nut height 8
da transition diameter 10 – 10.8
t groove depth 3.2 – 3.7
n groove width 3.5
mass mass per 1000 pieces (kg) 11.5 Thread · ISO 261/262
Pitch P 1.5
d2 9.026
d3 8.16
Tap drill 8.5
Stress area As 57.99 mm² Size sheet · DIN 546
M12
dk external diameter of the nut 21
m nut height 10
da transition diameter 12 – 13
t groove depth 3.8 – 4.3
n groove width 4
mass mass per 1000 pieces (kg) 21.5 Thread · ISO 261/262
Pitch P 1.75
d2 10.863
d3 9.853
Tap drill 10.25
Stress area As 84.27 mm² Size sheet · DIN 546
M14
dk external diameter of the nut 24
m nut height 11
da transition diameter 14 – 15.1
t groove depth 3.8 – 4.3
n groove width 4
mass mass per 1000 pieces (kg) 27.1 Thread · ISO 261/262
Pitch P 2
d2 12.701
d3 11.546
Tap drill 12
Stress area As 115.44 mm² Size sheet · DIN 546
M16
dk external diameter of the nut 26
m nut height 12
da transition diameter 16 – 17.3
t groove depth 3.8 – 4.3
n groove width 4
mass mass per 1000 pieces (kg) 36.8 Thread · ISO 261/262
Pitch P 2
d2 14.701
d3 13.546
Tap drill 14
Stress area As 156.67 mm² Size sheet · DIN 546
M18
dk external diameter of the nut 29
m nut height 13
da transition diameter 18 – 19.5
t groove depth 4.8 – 5.5
n groove width 4
mass mass per 1000 pieces (kg) 48.4 Thread · ISO 261/262
Pitch P 2.5
d2 16.376
d3 14.933
Tap drill 15.5
Stress area As 192.47 mm² Size sheet · DIN 546
M20
dk external diameter of the nut 32
m nut height 14
da transition diameter 20 – 21.6
t groove depth 4.8 – 5.5
n groove width 5
mass mass per 1000 pieces (kg) 57.2 Thread · ISO 261/262
Pitch P 2.5
d2 18.376
d3 16.933
Tap drill 17.5
Stress area As 244.79 mm² Provenance
Draft — values taken from a single source and not yet cross-checked.
fasteners.eu dimensions, lengths, materials, property classes, current norm, equivalent norms Accessed 2026-09-23 · For design and safety-critical use, consult the current edition of the standard.