材质 
M12
1.75
14.7
13
12.89
19.85
7.55
8.45
0.6
18
17.57
M16
2
18.7
17
16.89
26.17
9.25
10.75
0.6
24
23.16
M20
2.5
24.4
21
20.87
32.95
12.1
13.9
0.8
30
29.16
M22
2.5
26.4
23
22.87
35.03
13.1
14.9
0.8
32
31
M24
3
28.4
25
24.87
39.55
14.1
15.9
0.8
36
35
M27
3
32.4
28
27.87
45.2
16.1
17.9
1
41
40
M30
3.5
35.4
31
30.84
50.85
17.95
20.05
1
46
45