| Unified |
| Decimal |
| Whitworth |
| Metric |
| Tapping |
| Pilot Holes |
| Install |
| Fixings |
| Feedback |
| Catalogue |
WOODSCREWS
| Screw Gauge | Pilot Drill (mm) | Clearance Drill | |
| Soft Wood | Hard Wood | mm | |
| 4 | N/A | 1.70 | 2.80 |
| 6 | 1.50 | 2.10 | 3.40 |
| 7 | 1.70 | 2.30 | 3.80 |
| 8 | 1.80 | 2.50 | 4.10 |
| 10 | 2.10 | 2.70 | 4.90 |
| 12 | 2.50 | 3.10 | 5.60 |
SELF TAPPING SCREWS
| Screw Gauge | Thickness mm |
Thickness SWG |
Pilot Drill mm |
Clearance Drill mm |
| 4 | 26 | 2.00 | 2.90 | |
| 4 | 1 | 20 | 2.40 | 2.90 |
| 4 | 2 | 14 | 2.80 | 2.90 |
| 6 | 1 | 26 | 2.40 | 3.60 |
| 6 | 1.6 | 16 | 3.00 | 3.60 |
| 6 | 2.6 | 12 | 3.20 | 3.60 |
| 8 | 22 | 2.90 | 4.20 | |
| 8 | 1.6 | 16 | 3.60 | 4.20 |
| 8 | 3.2 | 10 | 4.00 | 4.20 |
| 10 | 22 | 3.60 | 5.00 | |
| 10 | 2.6 | 12 | 4.10 | 5.00 |
| 10 | 3.25 | 10 | 4.40 | 5.00 |
| 12 | 22 | 4.10 | 5.50 | |
| 12 | 16 | 4.40 | 5.50 | |
| 12 | 4.76 | 6 | 5.00 | 5.50 |
| 14 | 1.22 | 18 | 4.90 | 6.30 |
| 14 | 3.2 | 10 | 5.50 | 6.30 |
| 14 | 4.76 | 6 | 6.00 | 6.30 |
The above information is for guidence only and should not be used when working to stringent specifications.