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Pilot hole size for a #14 screw

The #14 is about the heaviest common wood screw — for heavy structural joints, large hinges and gate hardware, thick timber, and heavy-duty mounting that needs maximum hold.

At this size a pilot hole isn't optional: drive a #14 into hardwood or thick timber dry and you'll split the piece or snap the screw. Here's the right pilot bit for a #14 in every common material.

Change screw size

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

Pilot hole sizes for a #14 screw

SoftwoodPine, fir, cedar, spruce
5/32in0.156" · 4.0 mm

Forgiving to drive — but pilot near the ends so it doesn't split.

HardwoodOak, maple, walnut, birch
11/64in0.172" · 4.4 mm

Splits easily — don't skip the pilot, and drive the screw slowly.

PlywoodPlywood, OSB, sheet goods
5/32in0.156" · 4.0 mm

Back it with scrap so it won't splinter on the exit side.

MDFMDF, particleboard
11/64in0.172" · 4.4 mm

Dense — drill slowly and stay in from the edge, or it blows out.

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How to size a pilot hole

A pilot hole is a small guide hole you drill before the screw. Size it to the screw's root diameter — the solid core under the threads — and the threads still bite while the board isn't forced apart and split.

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

Common questions

What size hole should I predrill for a #14 screw?

For a #14 screw, drill a 5/32" (4.0 mm) pilot hole in softwood, or 11/64" (4.4 mm) in hardwood. Plywood uses the softwood size; MDF uses the hardwood size.

What drill bit do I use for a #14 screw?

Use a 5/32" bit for softwood and a 11/64" bit for hardwood. Those match the screw's root (inner) diameter, so the threads still grip but the wood isn't forced apart.

Is the pilot hole bigger in hardwood for a #14 screw?

Yes. Hardwood splits more easily, so a #14 screw takes a slightly larger 11/64" pilot hole versus 5/32" in softwood.

Do I need a pilot hole for a #14 screw in MDF?

Yes. MDF is dense and blows out near edges. Drill the hardwood size (11/64", 4.4 mm), go slowly, keep back from the edge, and use fine-thread screws.

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.