材质 
M12
1.75
14.7
12.7
11.3
22.78
7.95
7.05
0.6
21
20.16
M16
2
18.7
16.7
15.3
29.56
10.75
9.25
0.6
27
26.16
M20
2.5
23.24
20.84
19.16
37.29
13.4
11.6
0.8
34
33
M22
2.5
25.24
22.84
21.16
39.55
14.9
13.1
0.8
36
35
M24
3
27.64
24.84
23.16
45.2
15.9
14.1
1
41
40
M27
3
31.24
27.84
26.16
50.85
17.9
16.1
1.2
46
45
M30
3.5
34.24
30.84
29.16
55.37
19.75
17.65
1.2
50
49
M33
3.5
41
37
35
66.44
23.55
21.45
1.5
60
58.8