DRILL DIAMETERS FOR THREAD RECOMMENDATION TABLES
ISO UNIFIED COARSE THREAD
Tap UNC |
Max Interal Diameter mm |
Drill Diameter mm |
Ex1 |
nr 2-56 |
1.872 |
1.8 |
0 |
nr 3-48 |
2.146 |
2 |
0 |
nr 4-40 |
2.358 |
2.35 |
0 |
nr 5-40 |
2.697 |
2.65 |
0 |
nr 6-32 |
2.896 |
2.85 |
0 |
nr 8-32 |
3.513 |
3.5 |
0 |
nr10-24 |
3.962 |
3.9 |
0 |
nr12-24 |
4.597 |
4.5 |
0 |
1/4-20 |
5.268 |
5.1 |
0 |
5/15-18 |
6.734 |
6.6 |
0 |
3/8-16 |
8.164 |
8 |
0 |
7/16-14 |
9.55 |
9.4 |
0 |
1/2-13 |
11.013 |
10.8 |
0 |
9/16-12 |
12.456 |
12.2 |
0 |
5/8-11 |
13.868 |
13.5 |
0 |
3/4-10 |
16.833 |
16.5 |
0 |
7/8-9 |
19.748 |
19.5 |
0 |
1-8 |
22.598 |
22.25 |
0 |
1.1/8-7 |
25.349 |
25 |
0 |
1.1/4-7 |
28.524 |
28 |
0 |
1.3/8-6 |
31.12 |
30.5 |
0 |
1.1/2-6 |
34.295 |
34 |
0 |
1.3/4-5 |
39.814 |
39.5 |
0 |
2.41/2 |
45.598 |
45 |
0 | |