Thread prep
5/16-18 Tap Drill
Common shop chart tap drill for 5/16-18 UNC.
Last updated 2026-05-12Confidence: reference-derivedUNC
| Thread size | 5/16-18 |
|---|---|
| Tap drill | F |
| Decimal / mm | 0.257 in / 6.528 mm |
| Normal clearance | 0.332 in |
| Percent thread | 75% reference |