Dimensions mm · values as the standard states them Size P s e l M6 1 10
11.05
18
M8 1.25 13
14.38
24
M10 1.5 17
18.9
30
M12 1.75 19
21.1
36
M14 2 22
24.49
42
M16 2 24
26.75
48
M18 2.5 27
29.56
54
M20 2.5 30
33.53
60
M22 2.5 32
35.03
66
M24 3 36
39.98
72
M27 3 41
45.2
81
M30 3.5 46
50.85
90
M33 3.5 50
55.37
99
M36 4 55
60.79
108
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 6334
M6
s width across flats 10
e width across corners 11.05
l length of nut 18 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 6334
M8
s width across flats 13
e width across corners 14.38
l length of nut 24 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 6334
M10
s width across flats 17
e width across corners 18.9
l length of nut 30 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 6334
M12
s width across flats 19
e width across corners 21.1
l length of nut 36 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 6334
M14
s width across flats 22
e width across corners 24.49
l length of nut 42 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 6334
M16
s width across flats 24
e width across corners 26.75
l length of nut 48 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 6334
M18
s width across flats 27
e width across corners 29.56
l length of nut 54 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 6334
M20
s width across flats 30
e width across corners 33.53
l length of nut 60 Thread · ISO 261/262
Pitch P 2.5
d2 18.376
d3 16.933
Tap drill 17.5
Stress area As 244.79 mm² Size sheet · DIN 6334
M22
s width across flats 32
e width across corners 35.03
l length of nut 66 Thread · ISO 261/262
Pitch P 2.5
d2 20.376
d3 18.933
Tap drill 19.5
Stress area As 303.4 mm² Size sheet · DIN 6334
M24
s width across flats 36
e width across corners 39.98
l length of nut 72 Thread · ISO 261/262
Pitch P 3
d2 22.051
d3 20.319
Tap drill 21
Stress area As 352.5 mm² Size sheet · DIN 6334
M27
s width across flats 41
e width across corners 45.2
l length of nut 81 Thread · ISO 261/262
Pitch P 3
d2 25.051
d3 23.319
Tap drill 24
Stress area As 459.41 mm² Size sheet · DIN 6334
M30
s width across flats 46
e width across corners 50.85
l length of nut 90 Thread · ISO 261/262
Pitch P 3.5
d2 27.727
d3 25.706
Tap drill 26.5
Stress area As 560.59 mm² Size sheet · DIN 6334
M33
s width across flats 50
e width across corners 55.37
l length of nut 99 Thread · ISO 261/262
Pitch P 3.5
d2 30.727
d3 28.706
Tap drill 29.5
Stress area As 693.55 mm² Size sheet · DIN 6334
M36
s width across flats 55
e width across corners 60.79
l length of nut 108 Thread · ISO 261/262
Pitch P 4
d2 33.402
d3 31.093
Tap drill 32
Stress area As 816.72 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.
Data notes (1) Status (active/withdrawn) could not be confirmed from the sources used.