材质 
M12
1.75
15.23
12.43
11.57
22.78
7.95
7.05
1
21
20.16
M16
2
19.23
16.43
15.57
29.56
10.75
9.25
1
27
26.16
M20
2.5
24.32
20.52
19.48
37.29
13.4
11.6
1.5
34
33
M22
2.5
26.32
22.52
21.48
39.55
14.9
13.1
1.5
36
35
M24
3
28.32
24.52
23.48
45.2
15.9
14.1
1.5
41
40
M27
3
32.84
27.84
26.16
50.85
17.9
16.1
2
46
45
M30
3.5
35.84
30.84
29.16
55.37
19.75
17.65
2
50
49