DRILL DIAMETERS FOR THREAD RECOMMENDATION TABLES
TAPERED AMERICAN PIPE THREAD
Tap NPT |
Number of t.p.i. |
Drill Diameter mm |
Ex1 |
1/16 |
27 |
6.3 |
0 |
1/8 |
27 |
8.5 |
0 |
1/4 |
18 |
11 |
0 |
3/8 |
18 |
14.5 |
0 |
1/2 |
14 |
18 |
0 |
3/4 |
14 |
23 |
0 |
1 |
14 |
29 |
0 |
1.1/4 |
11.1/2 |
38 |
0 |
1.1/2 |
11.1/2 |
44 |
0 |
2 |
11.1/2 |
56 |
0 |
2.1/2 |
8 |
67 |
0 |
3 |
8 |
83 |
0 | |