# Keyhole hanger slot

> What size is a keyhole slot for a screw?

- Category: Joinery › 3D-print connectors
- Kind: Hardware
- Basis: Xem Studio design — geometry computed in the generator from traditional proportions
- Page: https://xemstudio.com/objects/keyhole-hanger-slot/ · JSON: https://xemstudio.com/api/geometry?object=keyhole-hanger-slot · Plain text: https://xemstudio.com/objects/keyhole-hanger-slot/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 |
|---|---|---|
| 50.0 | 80.0 | 15.0 |

**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).
- The hidden hanger on the back of signs, frames and printed wall mounts: the screw head enters the round hole and the plate slides down so the head sits in the pocket behind the slot.
- Sized for a screw with a Ø4–4.5 mm shank and a head up to 9 mm (e.g. #8 / 4 mm pan or round heads); scale the three numbers for other screws.

## Sizes

| dimension | value |
|---|---|
| stock | 6 mm back plate |
| parts | plate, screw stand in |
| entry hole | Ø9 mm (passes the head) |
| slot | 4.5 mm wide, 12 mm travel |
| head pocket | Ø9 mm, 3 mm deep behind the slot |
| assembles | over the screw head, slide down |
| holds | hangs flush on one screw; lift to remove |

## 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/keyhole-hanger-slot/index.json · license: https://xemstudio.com/files/hardware/keyhole-hanger-slot/LICENSE.md

- keyhole-hanger-slot-plate: [STEP](https://xemstudio.com/files/hardware/keyhole-hanger-slot/keyhole-hanger-slot-plate.step) · [STL](https://xemstudio.com/files/hardware/keyhole-hanger-slot/keyhole-hanger-slot-plate.stl) — Back plate with the keyhole: Ø9 entry, 4.5 mm slot, 3 mm deep head pocket
- keyhole-hanger-slot-screw-stand-in: [STEP](https://xemstudio.com/files/hardware/keyhole-hanger-slot/keyhole-hanger-slot-screw-stand-in.step) · [STL](https://xemstudio.com/files/hardware/keyhole-hanger-slot/keyhole-hanger-slot-screw-stand-in.stl) — Stand-in screw: Ø4.5 shank, Ø9 × 2 mm head, in the locked position
- keyhole-hanger-slot-assembled: [STEP](https://xemstudio.com/files/hardware/keyhole-hanger-slot/keyhole-hanger-slot-assembled.step) · [STL](https://xemstudio.com/files/hardware/keyhole-hanger-slot/keyhole-hanger-slot-assembled.stl) — All parts in their assembled position (each part its own solid)

## Questions

**How big should a keyhole be?**

Entry hole a bit bigger than the screw head, slot a bit wider than the shank, a pocket behind for the head.

## Fits with

- [French cleat dimensions: 45° on 3/4 in stock from a 5 in blank](https://xemstudio.com/objects/french-cleat/)
- [Snap-fit cantilever joint (hook and catch)](https://xemstudio.com/objects/snap-fit-cantilever-joint/)