---
title: "Which screw and pilot hole should I use for wood?"
description: "A pilot hole matching the screw's core diameter in the lower piece and a clearance hole in the upper one — that is what makes a joint tight. The ranked options, the "
url: https://atoneplace.net/which/screw-wood/
site: "At One Place"
---

# Which screw and pilot hole should I use for wood?

**Which screw and pilot hole should I use for wood?: A pilot hole matching the screw's core diameter in the lower piece and a clearance hole in the upper one — that is what makes a joint tight.**

A screwed timber joint is a clamp, and the geometry decides whether it clamps. The lower piece needs a pilot hole about the size of the screw's core so the thread has full material to bite into without splitting the wood, and the upper piece needs a clearance hole the screw slips through freely — otherwise the thread grabs the top piece and holds the two apart. Hardwood needs both holes and softwood usually only needs the pilot; near an end or an edge, both are essential because timber splits along the grain. Screw into end grain holds perhaps half as well as into face grain, which is why joinery uses dowels, biscuits or pocket holes instead of relying on it.

## The options, ranked

*Ranked best-first for the stated job. The third column is why the others exist.*

| Option | Good at | Bad at |
| --- | --- | --- |
| Countersunk woodscrew | The general-purpose fixing: ductile enough to bend rather than snap, and available in every size. | Needs a countersink cut in hardwood, or the head splits the surface. |
| Part-threaded screw | The plain shank near the head lets the top piece pull down tight against the bottom one. | Less thread engagement in thin material. |
| Fully threaded screw | Maximum grip along its length, right for holding two pieces already clamped together. | Holds the joint open if there is any gap, because it threads into both pieces. |
| Pocket-hole screw | Self-drilling with a flat washer head for end-grain joints where a normal screw would split. | Requires a jig, and the joint relies entirely on the screws. |

## Technique that changes the outcome

1. Pilot to the core diameter in the lower piece; hold the screw against the drill bit to compare
2. Drill a clearance hole in the upper piece so the shank slips through
3. Countersink so the head sits flush without wedging the grain apart
4. Wax the thread on hardwood — candle wax on the screw makes a striking difference

## What goes wrong

- Fully threaded screws where a joint needs to be pulled tight
- Screwing near an end without a pilot hole
- Relying on screws into end grain for anything structural

> Compiled practical guidance rather than a published standard. Product formulations vary by brand and market, so read the label — and where the work is structural, electrical or gas, the regulations that apply where you are govern rather than anything here.

## Other screw questions

| For | Use |
| --- | --- |
| Decking | Stainless steel — 304 inland, 316 near the coast — or a screw specifically rated for modern treated timber, which eats ordinary zinc plating. |
| Masonry | A concrete screw into a precisely sized hole, or a plug and screw — and hollow block needs a different anchor entirely. |
| Plasterboard | Coarse-thread bugle-head drywall screws into timber studs, fine-thread into metal studs — and never use them for anything structural. |
| MDF | A straight-shank MDF screw with a parallel thread, always into a pilot hole — the edge splits without one. |
| Sheet metal | A self-drilling (Tek) screw with a drill point matched to the material thickness, or a self-tapping screw into a correctly sized pilot hole. |
| Chipboard | A twin-thread chipboard screw with an unthreaded shank under the head, so it pulls the joint together instead of bursting the board. |
| Plastic | A thread-forming screw designed for plastic, or a heat-set threaded insert where the joint will be undone more than once. |
| Roofing sheets | A hex-head screw with a bonded EPDM washer, driven until the washer just spreads — no further. |
| Brass hardware | Cut the thread with a steel screw of the same size first, wax the brass one, and use a driver that fits the slot exactly. |

## Common questions

### Which screw and pilot hole should I use for wood?

A pilot hole matching the screw's core diameter in the lower piece and a clearance hole in the upper one — that is what makes a joint tight.

### What should I avoid?

Fully threaded screws where a joint needs to be pulled tight Screwing near an end without a pilot hole Relying on screws into end grain for anything structural

## Related pages

- [Which screw should I use for decking?](https://atoneplace.net/which/screw-decking/)
- [Which screw should I use in masonry?](https://atoneplace.net/which/screw-masonry/)
- [Which screw should I use for plasterboard?](https://atoneplace.net/which/screw-plasterboard/)
- [Which screw should I use in MDF?](https://atoneplace.net/which/screw-mdf/)
- [Which screw should I use for sheet metal?](https://atoneplace.net/which/screw-sheet-metal/)
- [Which screw should I use in chipboard?](https://atoneplace.net/which/screw-chipboard/)
- [Which screw should I use in plastic?](https://atoneplace.net/which/screw-plastic/)
- [Which screw should I use for roofing sheets?](https://atoneplace.net/which/screw-roofing/)
- [How do I drive brass screws without snapping them?](https://atoneplace.net/which/screw-brass-hardware/)
- [Which glue works on wood?](https://atoneplace.net/which/glue-wood/)
- [Which drill bit should I use for wood?](https://atoneplace.net/which/drill-bit-wood/)
- [Which circular saw blade for wood?](https://atoneplace.net/which/blade-wood/)

## Sources

- Typical range compiled from manufacturer specifications — At One Place (/about/)