Pilot hole size for a #7 screw
The #7 sits between the #6 and the everyday #8 — a light-to-medium screw for cabinet hardware, hinges and brackets, drawer slides, and general work where a #6 feels light but a #8 is a touch big.
Drilling a pilot hole first stops it splitting the board and makes it far easier to drive straight, especially in hardwood or near an edge. Here's the right pilot bit for a #7 in every common material.
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Covers #4–#14 wood screws — the common range.
Pilot hole sizes for a #7 screw
Forgiving to drive — but pilot near the ends so it doesn't split.
Splits easily — don't skip the pilot, and drive the screw slowly.
Back it with scrap so it won't splinter on the exit side.
Dense — drill slowly and stay in from the edge, or it blows out.
Clearance hole, top board: 5/32" · 4.0 mm — drilled in the top piece so the shank passes through freely and the screw pulls the joint tight.
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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.
Sizes above are shown as a fraction, a decimal and millimetres — to match any of them to the nearest actual bit, use the drill bit size converter.
Split-safe — when in doubt, start one size smaller and test on scrap.
Still splitting boards? How to keep wood from splitting when screwing.
Common questions
What size hole should I predrill for a #7 screw?
For a #7 screw, drill a 3/32" (2.4 mm) pilot hole in softwood, or 7/64" (2.8 mm) in hardwood. Plywood uses the softwood size; MDF uses the hardwood size.
What drill bit do I use for a #7 screw?
Use a 3/32" bit for softwood and a 7/64" 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 #7 screw?
Yes. Hardwood splits more easily, so a #7 screw takes a slightly larger 7/64" pilot hole versus 3/32" in softwood.
Do I need a pilot hole for a #7 screw in MDF?
Yes. MDF is dense and blows out near edges. Drill the hardwood size (7/64", 2.8 mm), go slowly, keep back from the edge, and use fine-thread screws.
Full pilot-hole chart
Wood screw pilot hole chart
| Screw | Softwood | Hardwood | Clearance |
|---|---|---|---|
| #2 | 1/16"1.6 mm | 1/16"1.6 mm | 3/32"2.4 mm |
| #3 | 1/16"1.6 mm | 5/64"2.0 mm | 7/64"2.8 mm |
| #4 | 1/16"1.6 mm | 5/64"2.0 mm | 1/8"3.2 mm |
| #5 | 5/64"2.0 mm | 3/32"2.4 mm | 1/8"3.2 mm |
| #6 | 5/64"2.0 mm | 3/32"2.4 mm | 9/64"3.6 mm |
| #7 | 3/32"2.4 mm | 7/64"2.8 mm | 5/32"4.0 mm |
| #8 | 7/64"2.8 mm | 1/8"3.2 mm | 11/64"4.4 mm |
| #9 | 1/8"3.2 mm | 9/64"3.6 mm | 3/16"4.8 mm |
| #10 | 1/8"3.2 mm | 9/64"3.6 mm | 3/16"4.8 mm |
| #12 | 9/64"3.6 mm | 5/32"4.0 mm | 7/32"5.6 mm |
| #14 | 5/32"4.0 mm | 11/64"4.4 mm | 1/4"6.4 mm |
Softwood / Hardwood = the pilot hole, drilled in the base piece · Plywood uses Softwood, MDF uses Hardwood (fine-thread).
Clearance = the shank hole in the top board, so the screw slips through and pulls the joint tight. Sized a touch larger than the shank on purpose.
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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.