Thread prep
1/2-13 Tap Drill
Common shop chart tap drill for 1/2-13 UNC.
Last updated 2026-05-12Confidence: reference-derivedUNC
| Thread size | 1/2-13 |
|---|---|
| Tap drill | 27/64 |
| Decimal / mm | 0.4219 in / 10.716 mm |
| Normal clearance | 0.531 in |
| Percent thread | 75% reference |