Dimensions mm · values as the standard states them Size P e m h a d2 d3 g1 g2 r1 r2 r3 r4 M4 0.7 18 – 20
3.2 – 4.6
8.5 – 10.5
≤ 2.1
6 – 8
5.5 – 7
1.1 – 1.9
1.7 – 2.3
≈ 3
≈ Radiused
≈ 0.5
≈ 2
M5 0.8 24 – 26
4 – 6.5
11 – 13
≤ 2.4
8 – 11
7.5 – 9
1.5 – 2.3
2.3 – 2.8
≈ 4
≈ Radiused
≈ 1
≈ 2.5
M6 1 30 – 33
5 – 8
15 – 17
≤ 3
10 – 13
9 – 11
1.5 – 2.3
2.7 – 3.3
≈ 5
≈ Radiused
≈ 1
≈ 3
M8 1.25 36 – 39
6.5 – 10
18 – 20
≤ 4
13 – 16
10.5 – 12.5
2 – 2.8
3.6 – 4.4
≈ 6
≈ Radiused
≈ 1
≈ 3
M10 1.5 48 – 51
8 – 12
23 – 25
≤ 4.5
17 – 20
14.5 – 16.5
3.6 – 4.4
4.6 – 5.4
≈ 8
≈ 1
≈ 1.2
≈ 5
M12 1.75 62 – 65
10 – 14
31 – 33.5
≤ 5.3
20 – 23
17.5 – 19.5
4.1 – 4.9
5.6 – 6.4
≈ 10
≈ 1
≈ 1.2
≈ 6
M16 2 70 – 73
13 – 17
35 – 37.5
≤ 6
26 – 29
21 – 23
5.6 – 6.4
6.5 – 7.5
≈ 11
≈ 1.2
≈ 1.6
≈ 7
M20 2.5 86 – 90
16 – 21
44 – 46.5
≤ 7.5
32 – 35
27 – 29
6.1 – 6.9
7 – 8
≈ 14
≈ 1.6
≈ 2
≈ 8
M24 3 106 – 110
20 – 25
53.5 – 56.5
≤ 8
41 – 44
35 – 37.5
8.6 – 9.4
9.5 – 10.5
≈ 18
≈ 2.5
≈ 2.5
≈ 9
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.
Length tolerances 6 5.4 – 6.6
8 7.3 – 8.7
10 9.3 – 10.7
12 11.1 – 12.9
14 13.1 – 14.9
16 15.1 – 16.9
18 17.1 – 18.9
20 19 – 21
25 24 – 26
30 29 – 31
35 33.8 – 36.2
40 38.8 – 41.2
50 48.8 – 51.2
60 58.5 – 61.5
Size sheet · DIN 316 D
M4
e width across corners 18 – 20
m head height 3.2 – 4.6
h head height including wings 8.5 – 10.5
a length undercut ≤ 2.1
d2 head diameter 6 – 8
d3 head diameter 5.5 – 7
g1 width of the wing 1.1 – 1.9
g2 width of the wing 1.7 – 2.3
r1 radius ≈ 3
r2 radius ≈ Radiused
r3 radius ≈ 0.5
r4 ≈ 2 Thread · ISO 261/262
Pitch P 0.7
d2 3.545
d3 3.141
Tap drill 3.3
Stress area As 8.78 mm² Standard lengths
6 · 8 · 10 · 12 · 14 · 16 · 18 · 20
Size sheet · DIN 316 D
M5
e width across corners 24 – 26
m head height 4 – 6.5
h head height including wings 11 – 13
a length undercut ≤ 2.4
d2 head diameter 8 – 11
d3 head diameter 7.5 – 9
g1 width of the wing 1.5 – 2.3
g2 width of the wing 2.3 – 2.8
r1 radius ≈ 4
r2 radius ≈ Radiused
r3 radius ≈ 1
r4 ≈ 2.5 Thread · ISO 261/262
Pitch P 0.8
d2 4.48
d3 4.019
Tap drill 4.2
Stress area As 14.18 mm² Standard lengths
8 · 10 · 12 · 14 · 16 · 18 · 20 · 25 · 30
Size sheet · DIN 316 D
M6
e width across corners 30 – 33
m head height 5 – 8
h head height including wings 15 – 17
a length undercut ≤ 3
d2 head diameter 10 – 13
d3 head diameter 9 – 11
g1 width of the wing 1.5 – 2.3
g2 width of the wing 2.7 – 3.3
r1 radius ≈ 5
r2 radius ≈ Radiused
r3 radius ≈ 1
r4 ≈ 3 Thread · ISO 261/262
Pitch P 1
d2 5.35
d3 4.773
Tap drill 5
Stress area As 20.12 mm² Standard lengths
8 · 10 · 12 · 14 · 16 · 18 · 20 · 25 · 30 · 35 · 40
Size sheet · DIN 316 D
M8
e width across corners 36 – 39
m head height 6.5 – 10
h head height including wings 18 – 20
a length undercut ≤ 4
d2 head diameter 13 – 16
d3 head diameter 10.5 – 12.5
g1 width of the wing 2 – 2.8
g2 width of the wing 3.6 – 4.4
r1 radius ≈ 6
r2 radius ≈ Radiused
r3 radius ≈ 1
r4 ≈ 3 Thread · ISO 261/262
Pitch P 1.25
d2 7.188
d3 6.466
Tap drill 6.75
Stress area As 36.61 mm² Standard lengths
10 · 12 · 14 · 16 · 18 · 20 · 25 · 30 · 35 · 40 · 50
Size sheet · DIN 316 D
M10
e width across corners 48 – 51
m head height 8 – 12
h head height including wings 23 – 25
a length undercut ≤ 4.5
d2 head diameter 17 – 20
d3 head diameter 14.5 – 16.5
g1 width of the wing 3.6 – 4.4
g2 width of the wing 4.6 – 5.4
r1 radius ≈ 8
r2 radius ≈ 1
r3 radius ≈ 1.2
r4 ≈ 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 Standard lengths
16 · 18 · 20 · 25 · 30 · 35 · 40 · 50
Size sheet · DIN 316 D
M12
e width across corners 62 – 65
m head height 10 – 14
h head height including wings 31 – 33.5
a length undercut ≤ 5.3
d2 head diameter 20 – 23
d3 head diameter 17.5 – 19.5
g1 width of the wing 4.1 – 4.9
g2 width of the wing 5.6 – 6.4
r1 radius ≈ 10
r2 radius ≈ 1
r3 radius ≈ 1.2
r4 ≈ 6 Thread · ISO 261/262
Pitch P 1.75
d2 10.863
d3 9.853
Tap drill 10.25
Stress area As 84.27 mm² Standard lengths
16 · 18 · 20 · 25 · 30 · 35 · 40 · 50 · 60
Size sheet · DIN 316 D
M16
e width across corners 70 – 73
m head height 13 – 17
h head height including wings 35 – 37.5
a length undercut ≤ 6
d2 head diameter 26 – 29
d3 head diameter 21 – 23
g1 width of the wing 5.6 – 6.4
g2 width of the wing 6.5 – 7.5
r1 radius ≈ 11
r2 radius ≈ 1.2
r3 radius ≈ 1.6
r4 ≈ 7 Thread · ISO 261/262
Pitch P 2
d2 14.701
d3 13.546
Tap drill 14
Stress area As 156.67 mm² Standard lengths
20 · 25 · 30 · 35 · 40 · 50 · 60
Size sheet · DIN 316 D
M20
e width across corners 86 – 90
m head height 16 – 21
h head height including wings 44 – 46.5
a length undercut ≤ 7.5
d2 head diameter 32 – 35
d3 head diameter 27 – 29
g1 width of the wing 6.1 – 6.9
g2 width of the wing 7 – 8
r1 radius ≈ 14
r2 radius ≈ 1.6
r3 radius ≈ 2
r4 ≈ 8 Thread · ISO 261/262
Pitch P 2.5
d2 18.376
d3 16.933
Tap drill 17.5
Stress area As 244.79 mm² Standard lengths
30 · 35 · 40 · 50 · 60
Size sheet · DIN 316 D
M24
e width across corners 106 – 110
m head height 20 – 25
h head height including wings 53.5 – 56.5
a length undercut ≤ 8
d2 head diameter 41 – 44
d3 head diameter 35 – 37.5
g1 width of the wing 8.6 – 9.4
g2 width of the wing 9.5 – 10.5
r1 radius ≈ 18
r2 radius ≈ 2.5
r3 radius ≈ 2.5
r4 ≈ 9 Thread · ISO 261/262
Pitch P 3
d2 22.051
d3 20.319
Tap drill 21
Stress area As 352.5 mm² Standard lengths
35 · 40 · 50 · 60
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.