Nominal Size
or Basic
Bolt Dia(d)
d1(14) H B C D D1
Basic Tol Basic Tol Basic Tol App App Min
M 12 12 ± 0.4 8 ± 0.8 22 0
± 0.8
25.4 20 20
16 10 27 31.2 25 25
M 20 20 0.8

0.4
13 ± 0.9 32 0

-1
37 30 29
M 22 20 14 36 41.6 34 33
M 24 24 15 41 47.3 39 38
M 27 27 17 46 53.1 44 43
M 30 30 19 ± 10 50 57.7 48 47
Nominal Size
or Basic
Bolt Dia(d)
r k a.b E F h S
app Max Max Max Basic Tol
M 12 0.8 ~ 1.6 2 0.7
0.8
0.9
1.1
0.4 ~ 0.8 25 ± 5
0
M 16 1.2 ~ 2.0 30
M 20 2.5 35 ± 6
0
M 22 40
M 24 1.6 ~ 2.4 3 1.2
1.3
45
M 27 50
M 30 2.0 ~ 2.8 3.5 3.5 55
Nominal Size
or Basic
Bolt Dia(d)
Major
Dia
H B C D D1 ab E F h
Basic Tol Basic Tol App App Min Max Max Max
M 12 12 12 ± 0.35 8 0
-0.8
25.4 20 20 0.5 0.4 ~0.8
M 16 16 16 10 31.2 25 25 0.8
M 20 20 20 ± 0.4 13 0
-1
37 30 29 0.9
M 22 22 22 14 41.6 34 33 1.1
M 24 24 24 15 47.3 39 38 1.2
M 27 27 29 17 53.1 44 43 1.3
M 30 30 30 19 57.7 48 47 1.5
Nominal Size
or Basic
Bolt Dia(d)
d D t corr
Basic Tol Basic Tol Basic Tol App
M 12 13 ± 0.7
0
26 ± 8 32 ± 0.4 1.5
M 16 17 32 0
-1
4.5 ± 0.5 2
M 20 21 ± 0.8
0
40
M 22 23 44 6 ± 0.7
M 24 25 48 2.4
M 27 28 56 0
-1.2
M 30 31 + 10.0 60 8 2.8