材质 
M8
1.25
5.5
5.2
9.7
8.82
9.18
2
0.4
4.3
4
7.78
8
M10
1.5
7
6.64
12.2
10.78
11.22
3
0.5
5.3
5
9.78
10
M12
1.75
8.5
8.14
14.7
12.78
13.22
3
0.6
6.3
6
11.73
12
M16
2
12
11.57
20.9
17.78
18.22
4
0.6
8.36
8
16.73
17
M20
2.5
15
14.57
27.1
22.58
23.42
5
0.8
10.36
10
21.67
22