1-8 Tap Drill Size
Use a 7/8" drill for a 1-8 UNC tap — .8750" (22.22 mm).
This drill gives roughly 75% thread, the standard for cut taps. For a form (roll) tap use the larger drill from the tap maker's chart.
Nearby taps
| Tap | Drill | Decimal |
|---|---|---|
| 7/8-14 UNF | 13/16 | .8125 |
| 1-12 UNF | 59/64 | .9219 |
Printable PDF version - Tap Drill Chart
Clean letter-size sheet for the toolbox or shop wall. Instant download, $3.49.
Clean letter-size sheet for the toolbox or shop wall. Instant download, $3.49.