Clearance holes for screws and fasteners
When you want a screw or bolt to pass through a design element it’s a good idea to use a clearance hole. While screws are normally smaller than the nominal size this doesn’t mean that you should use a 3mm hole for an M3 screw. Use one of the clearance hole sizes instead which allow for flexibility during assembly.
For example, if you’re using an M6 screw, make the hole it passes through 6.5mm in diameter – it’s a standard size drill that we will usually keep in stock!
| Nominal Size | Standard Drill Sizes | Tight Fit | Normal Fit | Loose Fit |
| 3 | 3.2 or 3.5 | 3.2 | 3.35 | 3.6 |
| 3.5 | 4 or 4.2 | 3.7 | 3.9 | 4.2 |
| 4 | 4.5 | 4.3 | 4.5 | 4.8 |
| 4.5 | 5 | 4.8 | 5 | 5.3 |
| 5 | 5.5 | 5.3 | 5.5 | 5.8 |
| 6 | 6.5, 7 | 6.4 | 6.5 | 7 |
| 7 | 7.5, 8 | 7.4 | 7.8 | 8 |
| 8 | 8.5, 9, or 10 | 8.4 | 9 | 10 |
| 10 | 10.5, 11, 12 | 10.5 | 11 | 12 |
| 12 | 13, 14, 15 | 13 | 14 | 15 |