# Living hinge (flexure hinge)

> How thick should a 3D printed living hinge be?

- Category: Joinery › 3D-print connectors
- Kind: Hardware
- Basis: Xem Studio design — geometry computed in the generator from traditional proportions
- Page: https://xemstudio.com/objects/living-hinge/ · JSON: https://xemstudio.com/api/geometry?object=living-hinge · Plain text: https://xemstudio.com/objects/living-hinge/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 | 40.0 | 3.0 |

**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).
- A thin flexible web between two thick parts: lids, cases, clips and boxes in one print. Polypropylene (PP) survives thousands of bends; PETG a few dozen; PLA cracks quickly.
- Print it flat with the web on the bed and the layers running across the hinge line, so each layer bends rather than splits.

## Sizes

| dimension | value |
|---|---|
| stock | 3 mm plates, 40 mm wide |
| parts | hinged plate |
| web | 0.5 mm thick, 6 mm long, at the bottom face |
| bends | about 180° in PP or TPU, a few times in PETG |
| assembles | prints flat, one piece |
| holds | two halves of a box, lid, clip or case together, hinged |

## 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 (2 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/living-hinge/index.json · license: https://xemstudio.com/files/hardware/living-hinge/LICENSE.md

- living-hinge-hinged-plate: [STEP](https://xemstudio.com/files/hardware/living-hinge/living-hinge-hinged-plate.step) · [STL](https://xemstudio.com/files/hardware/living-hinge/living-hinge-hinged-plate.stl) — Two 3 mm plates joined by a 0.5 mm web, 6 mm long
- living-hinge-assembled: [STEP](https://xemstudio.com/files/hardware/living-hinge/living-hinge-assembled.step) · [STL](https://xemstudio.com/files/hardware/living-hinge/living-hinge-assembled.stl) — All parts in their assembled position (each part its own solid)

## Questions

**How thick should a living hinge be?**

0.3–0.6 mm for PP or PETG; 0.5 mm here, 6 mm long.

**What filament is best for living hinges?**

Polypropylene (PP), then TPU; PETG lasts a few dozen bends; PLA cracks.

## Fits with

- [Print-in-place: barrel hinge, three knuckles, folds 180° (48.8 mm)](https://xemstudio.com/objects/print-in-place-barrel-hinge-180/)
- [Snap-fit cantilever joint (hook and catch)](https://xemstudio.com/objects/snap-fit-cantilever-joint/)