Tap Drill Sizes (inch)
| Tap Size | TPI | Thread Form | Tap Drill |
| - | 80 | - | 3/64 |
| 1 | 64 72 |
UNC UNF |
53 53 |
| 2 | 56 64 |
UNC UNF |
50 50 |
| 3 | 48 56 |
UNC UNF |
47 45 |
| 4 | 36 40 48 |
UNS UNC UNF |
44 43 42 |
| 5 | 40 44 |
UNC UNF |
38 37 |
| 6 | 32 40 |
UNC UNF |
36 33 |
| 8 | 32 36 |
UNC UNF |
29 29 |
| 10 | 24 32 |
UNC UNF |
25 21 |
| 12 | 24 28 |
UNC UNF |
16 14 |
| 1/4 | 20 28 |
UNC UNF |
7 3 |
| 5/16 | 18 24 |
UNC UNF |
F 1 |
| 3/8 | 16 24 |
UNC UNF |
5/16 Q |
| 7/16 | 14 20 |
UNC UNF |
U 25/64 |
| 1/2 | 13 20 |
UNC UNF |
27/64 29/64 |
| 9/16 | 12 18 |
UNC UNF |
31/64 33/64 |
| 5/8 | 11 18 |
UNC UNF |
17/32 37/64 |
| 11/16 | 11 16 |
UNC UNF |
19/32 5/8 |
| 3/4 | 10 16 |
UNC UNF |
21/32 11/16 |
| 7/8 | 9 14 |
UNC UNF |
49/64 13/16 |
| 1" | 8 12 14 |
UNC UNF UNS |
7/8 59/64 15/16 |
| 1 1/8 | 7 12 |
UNC UNF |
63/64 1 3/64 |
| 1 1/4 | 7 12 |
UNC UNF |
1 7/64 1 11/64 |
| 1 3/8 | 6 12 |
UNC UNF |
1 7/32 1 19/64 |
| 1 1/2 | 6 12 |
UNC UNF |
1 11/32 1 27/64 |