材质 
M12
1.75
19.85
15
13.2
3.5
3.98
18
17.57
9.46
10
M16
2
26.17
19
16.9
4.5
4.98
24
23.16
12.3
13
M20
2.5
32.95
22
19.9
4.5
4.98
30
29.16
15.3
16
M24
3
39.55
27
24.9
5.5
5.98
36
35
18.16
19
M27
3
45.2
30
27.9
5.5
5.98
41
40
21.16
22
M30
3.5
50.85
33
30.5
7
7.58
46
45
23.16
24
M33
3.5
55.37
35
32.5
7
7.58
50
49
25.16
26