絲攻加工下孔徑選用表

梅華
UNF美制細牙螺紋
螺紋尺寸
牙數
建議孔徑
最小尺寸
最大尺寸
NO.0
80
1.25
1.182
1.305
NO.1
72
1.55
1.474
1.612
NO.2
64
1.85
1.756
1.912
NO.3 
56
2.1
2.025
2.197
NO.4
48
2.4
2.271
2.458
NO.5
44
2.7
2.551
2.740
NO.6
40
2.9
2.820
3.022
NO.8
36
3.5
3.404
3.606
NO.10
32
4.1
3.963
4.165
NO.12
28
4.6
4.496
4.724
1/4
28
5.5
5.360
5.588
5/16
24
6.9
6.782
7.035
3/8
24
8.5
8.382
8.636
7/16
20
9.9
9.729
10.033
1/2
20
11.5
11.329
11.607
9/16
18
12.9
12.751
13.081
5/8
18
14.5
14.351
14.681
3/4
16
17.5
17.323
17.678
7/8
14
20.5
20.270
20.675
1
12
23.2
23.114
23.571
1 1/8
12
26.5
26.289
26.746
1 1/4
12
29.5
29.464
29.921
1 3/8
12
32.8
32.639
33.096
1 1/2
12
36
35.814
36.271