103
Te
ch
n
ic
al
d
at
a
* Knurl the side surface of the head. In this case, the dk (Maximum) shall be the values marked *2. For side surfaces with no knurling, the dk shall be the values marked *1.
* The column 1 of S (Maximum) is used for the strength class 8.8 and 10.9, and for the property class A2-50 and A2-70. The column 2 is applied to the strength class 12.9.
The column 1 can be applied to the strength class 12.9 by agreement of the parties concerned.
* The nominal diameters in parentheses are preferably not to be used.
Nominal designation of screw (d)
M1.6
M2
M2.5
M3
M4
M5
M6
M8
M10
M12
(M14)
M16
(M18)
M20
Pitch of screw (P)
0.35
0.4
0.45
0.5
0.7
0.8
1
1.25
1.5
1.75
2
2
2.5
2.5
b
Reference
15
16
17
18
20
22
24
28
32
36
40
44
48
52
dk
Max. (Basic dimension)*
1
3
3.8
4.5
5.5
7
8.5
10
13
16
18
21
24
27
30
Maximum *
2
3.14
3.98
4.68
5.68
7.22
8.72
10.22
13.27
16.27
18.27
21.33
24.33
27.33
30.33
Minimum
2.86
3.62
4.32
5.32
6.78
8.28
9.78
12.73
15.73
17.73
20.67
23.67
26.67
29.67
da
Maximum
2
2.6
3.1
3.6
4.7
5.7
6.8
9.2
11.2
13.7
15.7
17.7
20.2
22.4
ds
Max. (Basic dimension)
1.6
2
2.5
3
4
5
6
8
10
12
14
16
18
20
Minimum
1.46
1.86
2.36
2.86
3.82
4.82
5.82
7.78
9.78
11.73
13.73
15.73
17.73
19.67
e
Minimum
1.73
1.73
2.30
2.87
3.44
4.58
5.72
6.86
9.15
11.43
13.72
16.00
16.00
19.44
f
Maximum
0.34
0.51
0.51
0.51
0.60
0.60
0.68
1.02
1.02
1.45
1.45
1.45
1.87
2.04
k
Max. (Basic dimension)
1.6
2
2.5
3
4
5
6
8
10
12
14
16
18
20
Minimum
1.46
1.86
2.36
2.86
3.82
4.82
5.70
7.64
9.64
11.57
13.57
15.57
17.57
19.48
r
Minimum
0.1
0.1
0.1
0.1
0.2
0.2
0.25
0.4
0.4
0.6
0.6
0.6
0.6
0.8
s
Nominal disig. (Basic dimension)
1.5
1.5
2
2.5
3
4
5
6
8
10
12
14
14
17
Minimum
1.52
1.52
2.02
2.52
3.02
4.02
5.02
6.02
8.025
10.025
12.032
14.032
14.032
17.050
Maximum
Column 1
1.560
1.560
2.060
2.580
3.080
4.095
5.140
6.140
8.175
10.175
12.212
14.212
14.212
17.230
Column 2
1.545
1.545
2.045
2.560
3.080
4.095
5.095
6.095
8.155
10.115
12.142
14.142
14.142
17.230
t
Minimum
0.7
1
1.1
1.3
2
2.5
3
4
5
6
7
8
9
10
v
Maximum
0.16
0.2
0.25
0.3
0.4
0.5
0.6
0.8
1
1.2
1.4
1.6
1.8
2
dw
Minimum
2.72
3.40
4.18
5.07
6.53
8.03
9.38
12.33
15.33
17.23
20.17
23.17
25.87
28.87
w
Minimum
0.55
0.55
0.85
1.15
1.4
1.9
2.3
3.3
4
4.8
5.8
6.8
7.7
8.6
Unit [mm]
Roundness
e
da
ds
V
r
r
r
V
45°
(Max.)
120°
(Min.)
f
b (Reference)
K
d
r
g
t
w
s
Chamfering
Incomplete thread
(2P and below)
Chamfer the edge. It is not
necessary for M4 and below.
Cone base
f (Max.) = 1.7r (Max.)
r (Max.) =
r (Min.) =
da (Max.) −ds (Max.)
2
Rounded or
chamfered head
The maximum state of the
rad. under the head
Rounding or chamfering can be performed on the top or
bearing surface of the head. Any burr should be removed.
Depending on the value of
the appendix table
Internal chamfering can be
performed on the hexagon socket.
dk
s
dk
dw
da
ds
Technical Data
Nominal designation of screw
M1.6
M2
M2.5
M3
M4
M5
M6
M8
M10
M12
(M14)
M16
(M18)
M20
l
l
s and
l
g
Nominal
length
Min.
Max.
l
s
Min.
l
g
Max.
l
s
Min.
l
g
Max.
l
s
Min.
l
g
Max.
l
s
Min.
l
g
Max.
l
s
Min.
l
g
Max.
l
s
Min.
l
g
Max.
l
s
Min.
l
g
Max.
l
s
Min.
l
g
Max.
l
s
Min.
l
g
Max.
l
s
Min.
l
g
Max.
l
s
Min.
l
g
Max.
l
s
Min.
l
g
Max.
l
s
Min.
l
g
Max.
l
s
Min.
l
g
Max.
2.5
2.30
2.70
3
2.80
3.20
4
3.76
4.24
5
4.76
5.24
6
5.76
6.24
8
7.71
8.29
10
9.71
10.29
12
11.65
12.35
16
15.65
16.35
20
19.58
20.42
2
4
25
24.58
25.42
5.75 8
4.5
7
30
29.58 30.42
9.5 12 6.5 10
4
8
35
34.5
35.5
11.5 15
9
13
6
11
40
39.5
40.5
16.5 20 14 18 11 16 5.75 12
45
44.5
45.5
19 23 16 21 10.75 17 5.5 13
50
49.5
50.5
24 28 21 26 15.75 22 10.5 18 5.25 14
55
54.4
55.6
26 31 20.75 27 15.5 23 10.25 19
60
59.4
60.6
31 36 25.75 32 20.5 28 15.25 24 10 20
6
16
65
64.4
65.6
30.75 37 25.5 33 20.25 29 15 25 11 21 4.5 17
70
69.4
70.6
35.75 42 30.5 38 25.25 34 20 30 16 26 9.5 22 5.5 18
80
79.4
80.6
45.75 52 40.5 48 35.25 44 30 40 26 36 19.5 32 15.5 28
90
89.3
90.7
50.5 58 45.25 54 40 50 36 46 29.5 42 25.5 38
100
99.3
100.7
60.5 68 55.25 64 50 60 46 56 39.5 52 35.5 48
110
109.3
110.7
65.25 74 60 70 56 66 49.5 62 45.5 58
120
119.3
120.7
75.25 84 70 80 66 76 59.5 72 55.5 68
130
129.2
130.8
80 90 76 86 69.5 82 65.5 78
140
139.2
140.8
90 100 86 96 79.5 92 75.5 88
150
149.2
150.8
96 106 89.5 102 85.5 98
160
159.2
160.8
106 116 99.5 112 95.5 108
180
179.2
180.8
119.5 132 115.5 128
200 199.05 200.95
135.5 148
Unit [mm]
* The gray portion indicates the recommended nominal length (
l
). The nominal length (
l
) that is shorter than the dashed line position indicates a complete thread.
The incomplete thread length under head is about 3P.
Configuration and Dimension of Hexagon Socket
Head Cap Screws
(Excerpts from JIS B 1176-1988)
Summary of Contents for COUPLINGS
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