Dimensions mm · values as the standard states them Size P ds dk s k b da t dL r1 rs rt w M3 0.5 2.86 – 3
5.4 – 5.7
2
2.02 – 2.08
1.4 – 1.65
(18)
≤ 3.6
≥ 1.04
(2.6)
3.3 – 3.7
≥ 0.1
≥ 0.3
≥ 0.2
M4 0.7 3.82 – 4
7.24 – 7.6
2.5
2.52 – 2.58
1.95 – 2.2
(20)
≤ 4.7
≥ 1.3
(3.8)
4.2 – 4.6
≥ 0.2
≥ 0.4
≥ 0.3
M5 0.8 4.82 – 5
9.14 – 9.5
3
3.02 – 3.08
2.5 – 2.75
(22)
≤ 5.7
≥ 1.56
(5)
5.25 – 5.75
≥ 0.2
≥ 0.45
≥ 0.38
M6 1 5.82 – 6
10.07 – 10.5
4
4.02 – 4.095
3 – 3.3
(24)
≤ 6.8
≥ 2.08
(6)
5.65 – 6.15
≥ 0.25
≥ 0.5
≥ 0.74
M8 1.25 7.78 – 8
13.57 – 14
5
5.02 – 5.14
4.1 – 4.4
(28)
≤ 9.2
≥ 2.6
(7.7)
7.45 – 7.95
≥ 0.4
≥ 0.7
≥ 1.05
M10 1.5 9.78 – 10
17.07 – 17.5
6
6.02 – 6.14
5.2 – 5.5
(32)
≤ 11.2
≥ 3.12
(10)
9.2 – 9.8
≥ 0.4
≥ 0.7
≥ 1.45
M12 1.75 11.73 – 12
20.48 – 21
8
8.025 – 8.175
6.24 – 6.6
(36)
≤ 13.7
≥ 4.16
(12)
10.5 – 11.2
≥ 0.6
≥ 1.1
≥ 1.63
M16 2 15.73 – 16
27.48 – 28
10
10.025 – 10.175
8.44 – 8.8
(44)
≤ 17.7
≥ 5.2
(16)
14.5 – 15.3
≥ 0.6
≥ 1.1
≥ 2.25
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 · ISO 7380-1
M3
ds shank diameter 2.86 – 3
dk head diameter 5.4 – 5.7
s width across flats 2
k head height 1.4 – 1.65
b thread length (18)
da transition diameter ≤ 3.6
t ≥ 1.04
dL (2.6)
r1 3.3 – 3.7
rs ≥ 0.1
rt ≥ 0.3
w ≥ 0.2 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 · ISO 7380-1
M4
ds shank diameter 3.82 – 4
dk head diameter 7.24 – 7.6
s width across flats 2.5
k head height 1.95 – 2.2
b thread length (20)
da transition diameter ≤ 4.7
t ≥ 1.3
dL (3.8)
r1 4.2 – 4.6
rs ≥ 0.2
rt ≥ 0.4
w ≥ 0.3 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 · ISO 7380-1
M5
ds shank diameter 4.82 – 5
dk head diameter 9.14 – 9.5
s width across flats 3
k head height 2.5 – 2.75
b thread length (22)
da transition diameter ≤ 5.7
t ≥ 1.56
dL (5)
r1 5.25 – 5.75
rs ≥ 0.2
rt ≥ 0.45
w ≥ 0.38 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 · ISO 7380-1
M6
ds shank diameter 5.82 – 6
dk head diameter 10.07 – 10.5
s width across flats 4
k head height 3 – 3.3
b thread length (24)
da transition diameter ≤ 6.8
t ≥ 2.08
dL (6)
r1 5.65 – 6.15
rs ≥ 0.25
rt ≥ 0.5
w ≥ 0.74 Thread · ISO 261/262
Pitch P 1
d2 5.35
d3 4.773
Tap drill 5
Stress area As 20.12 mm² Size sheet · ISO 7380-1
M8
ds shank diameter 7.78 – 8
dk head diameter 13.57 – 14
s width across flats 5
k head height 4.1 – 4.4
b thread length (28)
da transition diameter ≤ 9.2
t ≥ 2.6
dL (7.7)
r1 7.45 – 7.95
rs ≥ 0.4
rt ≥ 0.7
w ≥ 1.05 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 · ISO 7380-1
M10
ds shank diameter 9.78 – 10
dk head diameter 17.07 – 17.5
s width across flats 6
k head height 5.2 – 5.5
b thread length (32)
da transition diameter ≤ 11.2
t ≥ 3.12
dL (10)
r1 9.2 – 9.8
rs ≥ 0.4
rt ≥ 0.7
w ≥ 1.45 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 · ISO 7380-1
M12
ds shank diameter 11.73 – 12
dk head diameter 20.48 – 21
s width across flats 8
k head height 6.24 – 6.6
b thread length (36)
da transition diameter ≤ 13.7
t ≥ 4.16
dL (12)
r1 10.5 – 11.2
rs ≥ 0.6
rt ≥ 1.1
w ≥ 1.63 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 · ISO 7380-1
M16
ds shank diameter 15.73 – 16
dk head diameter 27.48 – 28
s width across flats 10
k head height 8.44 – 8.8
b thread length (44)
da transition diameter ≤ 17.7
t ≥ 5.2
dL (16)
r1 14.5 – 15.3
rs ≥ 0.6
rt ≥ 1.1
w ≥ 2.25 Thread · ISO 261/262
Pitch P 2
d2 14.701
d3 13.546
Tap drill 14
Stress area As 156.67 mm² Provenance
Reviewed — dimensions cross-checked against the official ISO preview; values match.
Accessed 2026-09-23 · For design and safety-critical use, consult the current edition of the standard.
Data notes (2) Dimensions cross-checked against the official ISO 7380-1:2022 preview — values match. Parameters that did not match the current ISO edition were omitted: dw, e.