圆柱头用沉孔尺寸：摘自GB/T 152.3-1988
| 螺纹规格d |
d2 |
t |
d3 |
d1 |
| 1.6 |
3.3 |
1.8 |
- |
1.8 |
| 2 |
4.3 |
2.3 |
- |
2.4 |
| 2.5 |
5 |
2.9 |
- |
2.9 |
| 3 |
6 |
3.4 |
- |
3.4 |
| 4 |
9 |
4.6 |
- |
4.5 |
| 5 |
10 |
5.7 |
- |
5.5 |
| 6 |
11 |
6.8 |
- |
6.6 |
| 8 |
15 |
9 |
- |
9 |
| 10 |
18 |
11 |
- |
11 |
| 12 |
20 |
13 |
16 |
13.5 |
| 14 |
24 |
15 |
18 |
15.5 |
| 16 |
26 |
17.5 |
20 |
17.5 |
| 20 |
33 |
21.5 |
24 |
22 |
| 24 |
40 |
25.5 |
28 |
26 |
| 30 |
48 |
32 |
36 |
33 |
| 36 |
57 |
38 |
42 |
39 |
