材质 
M6
1
6
5.82
17
16.73
5
4.82
12
M8
1.25
8
7.78
20
19.67
6
5.82
16
M10
1.5
10
9.78
28
27.67
7
6.78
18
M12
1.75
12
11.73
35
34.61
8
7.78
22
M16
2
16
15.73
42
41.61
9
8.78
26
M20
2.5
20
19.67
52
51.54
10
9.78
30
M24
3
24
23.67
63
62.54
12
11.73
36
M30
3.5
28
27.67
75
74.54
14
13.73
45