# Plain flat-belt pulley Ø40 × 100 face, Ø8 bore (no flanges)

> What is a plain Ø40 flat-belt pulley for?

- Category: Hardware › Mechanism parts
- Kind: Modern device
- Basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance
- Page: https://xemstudio.com/objects/plain-flat-pulley-40x100/ · JSON: https://xemstudio.com/api/geometry?object=plain-flat-pulley-40x100 · Plain text: https://xemstudio.com/objects/plain-flat-pulley-40x100/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 |
|---|---|---|
| 40.0 | 40.0 | 100.0 |

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

## Notes

- Ø40 × 100 mm straight face, Ø8 bore, no flanges: the face is exactly the belt's width, so a twisted belt can leave it at an angle (quarter-turn and guide-pulley drives) without riding over a flange.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

## Sizes

| dimension | value |
|---|---|
| face | Ø40 × 100 mm |
| bore | Ø8 |
| flanges | none |

## 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. 256: figure, his text and an animation](https://507movements.com/mm_256.html) — web — Publisher's page; dimensions are facts
- Xem Studio: [drawing](https://xemstudio.com/objects/quarter-turn-belt-drive-mechanism/) — web — Publisher's page; dimensions are facts

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

Index: https://xemstudio.com/files/hardware/plain-flat-pulley-40x100/index.json · license: https://xemstudio.com/files/hardware/plain-flat-pulley-40x100/LICENSE.md

- plain-flat-pulley-40x100: [STEP](https://xemstudio.com/files/hardware/plain-flat-pulley-40x100/plain-flat-pulley-40x100.step) · [STL](https://xemstudio.com/files/hardware/plain-flat-pulley-40x100/plain-flat-pulley-40x100.stl) — pulley, axis Z, centred on z = 0

## Questions

**What is a plain Ø40 flat-belt pulley for?**

Ø40 × 100 mm straight face, Ø8 bore, no flanges: the face is exactly the belt's width, so a twisted belt can leave it at an angle (quarter-turn and guide-pulley drives) without riding over a flange.

## Fits with

- [Quarter-turn belt between shafts at right angles (no guide pulleys)](https://xemstudio.com/objects/quarter-turn-belt-drive-mechanism/)
- [Three speeds by shifting a belt over pulleys carrying gears (16 / 24 / 32 T)](https://xemstudio.com/objects/belt-shifted-gears-three-speed-mechanism/)