材质 
M12
1.75
15.2
12.7
11.3
21
8.8
7.2
16
1.2
8
7.4
8.36
M16
2
19.2
16.7
15.3
27
10.8
9.2
18
1.2
11.6
11
12.43
M20
2.5
24.4
20.84
19.16
34
13.9
12.1
20
1.5
14.4
13.8
15.6
M22
2.5
26.4
22.84
21.16
38.5
14.9
13.1
21
1.5
15.7
15.1
17.06
M24
3
28.4
24.84
23.16
43
15.9
14.1
21.5
1.5
17.1
16.5
18.65
M27
3
32.4
27.84
26.16
48
17.9
16.1
24
2
19.3
18.7
21.13
M30
3.5
35.4
30.84
29.16
52
20
18
26
2
21.4
20.8
23.5