What Drill Bit

What drill bit do I need?

Pick your screw size and what you're drilling into — we'll give you the one pilot-hole bit to grab, so you don't split your board.

Screw size

Covers #4–#14 wood screws — the common range.

Drilling into

Drill this pilot bit

Get the gear

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Why this size

Your pilot hole matches the screw's inner core — the solid part under the threads — so the threads still bite, but the wood isn't forced apart.

Split-safe — when in doubt, start one size smaller and test on scrap.

Full pilot-hole chart

Straight-bit pilot sizes · fraction / mm · verified #4–#14
ScrewSoftwoodHardwood
#41/16"1.6 mm5/64"2.0 mm
#65/64"2.0 mm3/32"2.4 mm
#87/64"2.8 mm1/8"3.2 mm
#101/8"3.2 mm9/64"3.6 mm
#129/64"3.6 mm5/32"4.0 mm
#145/32"4.0 mm11/64"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).

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.