材质 
M12
1.75
22.78
21
20.67
12.3
11.87
M14
2
26.17
24
23.16
15.3
14.6
M16
2
29.56
27
26.16
17.1
16.4
M18
2.5
32.95
30
29.16
18.8
17.5
M20
2.5
37.29
34
33
20.7
19.4
M22
2.5
39.55
36
35
23.6
22.3
M24
3
45.2
41
40
24.2
22.9
M27
3
50.85
46
45
27.6
26.3
M30
3.5
55.37
50
49
30.7
29.1
M33
3.5
60.79
55
53.8
34.2
32.6
M36
4
66.44
60
58.8
36.8
35.2
M39
4
72.02
65
63.8
40
37.8
M42
4.5
76.95
70
68.1
43
41