材质 
M12
1.75
20.03
18
17.73
10.8
10.37
M14
2
23.35
21
20.67
12.8
12.1
M16
2
26.75
24
23.67
14.8
14.1
M18
2.5
29.56
27
26.16
15.8
15.1
M20
2.5
32.95
30
29.16
18
16.9
M22
2.5
37.29
34
33
19.4
18.1
M24
3
39.55
36
35
21.5
20.2
M27
3
45.2
41
40
23.8
22.5
M30
3.5
50.85
46
45
25.6
24.3
M33
3.5
55.37
50
49
28.7
27.4
M36
4
60.79
55
53.8
31
29.4
M39
4
66.44
60
58.8
33.4
31.8
M42
4.5
72.02
65
63.8
34
32.4