六角头螺栓—细杆—B级（摘自GB 5784-86)
螺纹M3～M20、细杆、B级的六角头螺栓。
标记示例：
螺纹d＝M12、公称长度l＝80mm、性能等级为5.8级、不经表面处理、B级的六角头螺栓的标记：
螺栓 GB 5784 M12×80
螺纹M3～M20、细杆的六角头螺栓：
|
螺纹规格
d
|
b参考
|
da
max
|
dw
min
|
e
min
|
K
|
K′
min
|
r
min
|
s
|
x
max
|
l
|
lg
|
|
l≤125
|
125＜l≤200
|
公称
|
min
|
max
|
max
|
min
|
min
|
max
|
|
M3
|
12
|
—
|
3.6
|
4.4
|
5.98
|
2
|
1.80
|
2.20
|
1.3
|
0.1
|
5.5
|
5.20
|
1.25
|
20～35
|
7～17
|
8～18
|
|
M4
|
14
|
—
|
4.7
|
5.7
|
7.50
|
2.8
|
2.60
|
3.00
|
1.8
|
0.2
|
7
|
6.64
|
1.75
|
20～40
|
4.6～24.6
|
6～26
|
|
M5
|
16
|
—
|
5.7
|
6.7
|
8.63
|
3.5
|
3.26
|
3.74
|
2.3
|
0.2
|
8
|
7.64
|
2
|
25～50
|
7.4～32.4
|
9～34
|
|
M6
|
18
|
—
|
6.8
|
8.7
|
10.89
|
4
|
3.76
|
4.24
|
2.6
|
0.25
|
10
|
9.64
|
2.5
|
25～60
|
5～40
|
7～42
|
|
M8
|
22
|
28
|
9.2
|
11.4
|
14.20
|
5.3
|
5.06
|
5.54
|
3.5
|
0.4
|
13
|
12.57
|
3.2
|
30～80
|
5.5～55.5
|
8～58
|
|
M10
|
26
|
32
|
11.2
|
14.4
|
17.59
|
6.4
|
6.11
|
6.69
|
4.3
|
0.4
|
16
|
15.57
|
3.8
|
40～100
|
11～71
|
14～74
|
|
M12
|
30
|
36
|
13.7
|
16.4
|
19.85
|
7.5
|
7.21
|
7.79
|
5
|
0.6
|
18
|
17.57
|
4.3
|
45～120
|
11.5～86.5
|
15～90
|
|
(M14)
|
34
|
40
|
15.7
|
19.2
|
22.78
|
8.8
|
8.51
|
9.09
|
6
|
0.6
|
21
|
20.16
|
5
|
50～140
|
12～96
|
16～100
|
|
M16
|
38
|
44
|
17.7
|
22
|
26.17
|
10
|
9.71
|
10.29
|
6.8
|
0.6
|
24
|
23.16
|
5
|
55～150
|
13～102
|
17～106
|
|
M20
|
46
|
52
|
22.4
|
27.7
|
32.95
|
12.5
|
12.15
|
12.85
|
8.5
|
0.8
|
30
|
29.16
|
6.3
|
65～150
|
14～93
|
19～98
|
注：尽可能不采用括号内的规格。
l的范围：
|
公称
|
20
|
25
|
30
|
35
|
40
|
45
|
50
|
55
|
60
|
65
|
70
|
80
|
90
|
100
|
110
|
120
|
130
|
140
|
150
|
|
min
|
18.9
|
23.9
|
28.9
|
33.7
|
38.7
|
43.7
|
48.7
|
53.5
|
58.5
|
63.5
|
68.5
|
78.5
|
88.3
|
98.3
|
108.3
|
118.3
|
128
|
138
|
148
|
|
max
|
21.1
|
26.1
|
31.1
|
36.3
|
41.3
|
46.3
|
51.3
|
56.5
|
61.5
|
66.5
|
71.5
|
81.5
|
91.7
|
101.7
|
111.7
|
121.7
|
132
|
142
|
152
|
