Shop reference tools
Clearance Hole Chart
Compare close-fit and free-fit clearance holes for common screws and bolts.
Clearance Hole Chart lookup
Start with the table, then use the related pages for tapping, clearance holes, pilot holes, and printable shop sheets.
| Fastener | Nominal diameter | Close fit | Free fit | Use note |
|---|---|---|---|---|
| #8 screw | 0.164 in | 11/64 in | 3/16 in | Use close fit for alignment; free fit when parts need assembly clearance. |
| #10 screw | 0.190 in | 13/64 in | 7/32 in | A printed or painted part may need the larger free-fit hole. |
| 1/4 bolt | 0.250 in | 17/64 in | 9/32 in | Close fit is common for locating; free fit is easier for field assembly. |
| 5/16 bolt | 0.313 in | 21/64 in | 11/32 in | Check washer bearing area if oversizing the hole. |
| 3/8 bolt | 0.375 in | 13/32 in | 7/16 in | Choose fit based on alignment and coating thickness. |
| 1/2 bolt | 0.500 in | 17/32 in | 9/16 in | Verify against your fastener standard for critical work. |
Related references
Screw Size ChartFind screw size references, pilot holes, and clearance hole starting points.Pilot Hole vs Clearance HoleThe difference between pilot holes, tap drill holes, and clearance holes with practical examples.Drill Size ChartFind fractional, number, letter, and metric drill sizes with decimal inch and millimeter equivalents.