材质 
M10
1.5
17.77
8.4
8.04
16
15.73
M12
1.75
20.03
10.8
10.37
18
17.73
M16
2
26.75
14.8
14.1
24
23.67
M20
2.5
32.95
18
16.9
30
29.16
M24
3
39.55
21.5
20.2
36
35
M27
3
45.2
23.8
22.5
41
40
M30
3.5
50.85
25.6
24.3
46
45
M33
3.5
55.37
28.7
27.4
50
49