# Half lap joint (corner)

> What are the proportions of a half lap joint?

- Category: Joinery › Lap & halving joints
- Kind: Hardware
- Basis: Xem Studio design — geometry computed in the generator from traditional proportions
- Page: https://xemstudio.com/objects/half-lap-joint/ · JSON: https://xemstudio.com/api/geometry?object=half-lap-joint · Plain text: https://xemstudio.com/objects/half-lap-joint/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files Xem Studio Design License (free to use and sell from, not to redistribute as files: https://xemstudio.com/license/)
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

## Overall (mm)

| length | width | height |
|---|---|---|
| 60.0 | 60.0 | 20.0 |

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- Woodworking joint drawn for 3D printing: the parts lock together by shape, so a print can be joined without glue or screws. Drawn at true size with the parts line to line (zero gap) in their assembled position — add your printer's fit allowance to the mating faces (your AI or slicer can do this).
- Each member is cut to half its thickness over one stock width, so the corner is flush on both faces.
- For a 3D print, print both parts flat (lap face up) and pin the corner with a Ø3–5 mm pin or a screw if it must not lift.

## Sizes

| dimension | value |
|---|---|
| stock | 20 × 20 mm square |
| parts | part a, part b |
| lap length | 20 mm (one stock width) |
| lap depth | 10 mm (half the thickness) on each part |
| assembles | B drops onto A from above |
| holds | racking in the plane of the frame; needs a pin or screw against lifting |

## Where the files are

- Xem Studio: [Joinery design (geometry computed in the generator from traditional proportions)](https://xemstudio.com/) — web — Xem Studio design

## Free STEP/STL (3 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/half-lap-joint/index.json · license: https://xemstudio.com/files/hardware/half-lap-joint/LICENSE.md

- half-lap-joint-part-a: [STEP](https://xemstudio.com/files/hardware/half-lap-joint/half-lap-joint-part-a.step) · [STL](https://xemstudio.com/files/hardware/half-lap-joint/half-lap-joint-part-a.stl) — Member A: lower half removed over the lap
- half-lap-joint-part-b: [STEP](https://xemstudio.com/files/hardware/half-lap-joint/half-lap-joint-part-b.step) · [STL](https://xemstudio.com/files/hardware/half-lap-joint/half-lap-joint-part-b.stl) — Member B: upper half removed over the lap
- half-lap-joint-assembled: [STEP](https://xemstudio.com/files/hardware/half-lap-joint/half-lap-joint-assembled.step) · [STL](https://xemstudio.com/files/hardware/half-lap-joint/half-lap-joint-assembled.stl) — All parts in their assembled position (each part its own solid)

## Questions

**How deep is a half lap?**

Half the stock thickness on each part: 10 mm here, over a lap one stock width (20 mm) long.

**Can you 3D print a half lap joint?**

Yes — both parts print flat; add your fit allowance to the two lap faces.

## Fits with

- [Cross lap joint (cross halving)](https://xemstudio.com/objects/cross-lap-joint/)
- [Tee halving joint (T-lap)](https://xemstudio.com/objects/tee-halving-joint/)
- [Dovetail halving joint (dovetail lap)](https://xemstudio.com/objects/dovetail-halving-joint/)
- [Half lap splice joint](https://xemstudio.com/objects/half-lap-splice-joint/)