# Ball-and-socket joint for tubing

> How does a ball-and-socket joint connect two tubes at an angle?

- Category: Mechanisms › Couplings & joints
- Kind: Hardware
- Basis: Xem Studio design following Brown No. 249 (1868)
- Page: https://xemstudio.com/objects/tube-ball-and-socket-joint-mechanism/ · JSON: https://xemstudio.com/api/geometry?object=tube-ball-and-socket-joint-mechanism · Plain text: https://xemstudio.com/objects/tube-ball-and-socket-joint-mechanism/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/)

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

## Notes

- One tube ends in a ball with the bore running through it; the other ends in a spherical cup. A ring with a spherical seat is screwed over the ball and holds it in the cup, so the first tube can be swung in any direction about the ball's centre while the bores stay connected.
- Ø30 ball, R15 cup and cap seat (line on line), Ø8 bore; drawn with the ball's tube tilted 15°. M3 cap screws not drawn.
- Brown's No. 249 (ball-and-socket joint for tubing).
- Parts (each has its own page): ball-end-tube-d30-12x8, ball-joint-socket-d40-cup-r15, ball-joint-cap-d40-r15.
- Brown's movement No. 249 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

## Sizes

| parameter | value |
|---|---|
| ball | Ø30 |
| bore | Ø8 |
| tilt drawn | 15° |
| cap screws | 3 × M3 |

## Where the files are

- Henry T. Brown (1868, public domain): [Five Hundred and Seven Mechanical Movements — scan on archive.org](https://archive.org/details/fivehundredseven00browiala) — web — Publisher's page; dimensions are facts
- 507movements.com: [Brown's movement No. 249: figure, his text and an animation](https://507movements.com/mm_249.html) — web — Publisher's page; dimensions are facts

## Free STEP/STL (1 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/tube-ball-and-socket-joint-mechanism/index.json · license: https://xemstudio.com/files/hardware/tube-ball-and-socket-joint-mechanism/LICENSE.md

- tube-ball-and-socket-joint-mechanism-assembly: [STEP](https://xemstudio.com/files/hardware/tube-ball-and-socket-joint-mechanism/tube-ball-and-socket-joint-mechanism-assembly.step) · [STL](https://xemstudio.com/files/hardware/tube-ball-and-socket-joint-mechanism/tube-ball-and-socket-joint-mechanism-assembly.stl) — Assembled mechanism, all parts placed at one pose (STEP keeps each part separate)

## Questions

**How does a ball-and-socket joint connect two tubes at an angle?**

One tube ends in a ball with the bore running through it; the other ends in a spherical cup. A ring with a spherical seat is screwed over the ball and holds it in the cup, so the first tube can be swung in any direction about the ball's centre while the bores stay connected.

## Fits with

- [Ball-ended tube: Ø30 ball on a Ø12 tube, Ø8 bore through](https://xemstudio.com/objects/ball-end-tube-d30-12x8/)
- [Ball-joint socket: Ø40 body with an R15 hemispherical cup on a Ø12 tube, 3 × Ø2.5 (M3 tap) holes](https://xemstudio.com/objects/ball-joint-socket-d40-cup-r15/)
- [Ball-joint cap: Ø40 × 8 ring with an R15 spherical seat and 3 × Ø3.4 holes](https://xemstudio.com/objects/ball-joint-cap-d40-r15/)