1/4-20 Tap Drill Size
Use a #7 drill for a 1/4-20 UNC tap — .2010" (5.11 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 |
|---|---|---|
| #10-32 UNF | #21 | .1590 |
| 1/4-28 UNF | #3 | .2130 |
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.