Wood screw pilot hole chart
Straight-bit pilot-hole sizes for every common wood screw, #4 through #14. Fractions and millimetres, for softwood and hardwood.
| Screw | Softwood | Hardwood |
|---|---|---|
| #4 | 1/16"1.6 mm | 5/64"2.0 mm |
| #6 | 5/64"2.0 mm | 3/32"2.4 mm |
| #8 | 7/64"2.8 mm | 1/8"3.2 mm |
| #10 | 1/8"3.2 mm | 9/64"3.6 mm |
| #12 | 9/64"3.6 mm | 5/32"4.0 mm |
| #14 | 5/32"4.0 mm | 11/64"4.4 mm |
Softwood — pine, fir, cedar, spruce · Plywood uses the Softwood column.
Hardwood — oak, maple, walnut, birch · MDF uses the Hardwood column (use fine-thread screws).
How to read it
Each row is the pilot-hole drill bit for that screw gauge. Plywood follows the softwood column; MDF follows the hardwood column.
Split-safe — when in doubt, start one size smaller and test on scrap.
Where these numbers come from
Straight-bit pilot sizes for modern wood screws, sized to the screw’s root diameter — a standard woodworking approach for a hole that grips without splitting — and cross-referenced against widely used charts (Bolt Depot, McFeely’s, WorkshopCalc). We lean slightly larger than the strength-optimized minimums, because for most projects not splitting the board matters more than maximum holding power. Plywood follows softwood; MDF follows hardwood / fine-thread practice.