US Tap and Drill Bit Size Table
| Tap | Fractional Drill Bit | Number Drill Bit | Letter Drill Bit |
|---|---|---|---|
| 0-80 | 3/64 | - | - |
| 1-64 | - | 53 | - |
| 2-56 | - | 50 | - |
| 3-48 | - | 47 | - |
| 4-40 | 3/32 | 43 | - |
| 5-40 | - | 38 | - |
| 6-32 | 7/64 | 35 | - |
| 8-32 | - | 29 | - |
| 10-24 | 5/32 | 25 | - |
| 10-32 | 5/32 | 21 | - |
| 12-24 | 11/64 | 16 | - |
| 1/4-20 | 13/64 | 7 | - |
| 1/4-28 | 7/32 | 3 | - |
| 5/16-18 | 17/64 | - | F |
| 5/16-24 | - | - | I |
| 3/8-16 | 5/16 | - | - |
| 3/8-24 | 21/64 | - | Q |
| 7/16-14 | 23/64 | - | U |
| 7/16-20 | 25/64 | - | - |
| 1/2-13 | 27/64 | - | - |
| 1/2-20 | 29/64 | - | - |
| 9/16-12 | 31/64 | - | - |
| 9/16-18 | 33/64 | - | - |
| 5/8-11 | 17/32 | - | - |
| 5/8-18 | 37/64 | - | - |
| 3/4-10 | 21/32 | - | - |
| 3/4-16 | 11/16 | - | - |
| Drill sizes are for 75% depth of thread. | |||
