# Spur gears, module 0.5: 10 to 80 teeth (20° involute)

> What is the pitch diameter of a module 0.5 spur gear?

- Category: Hardware › Motion
- Kind: Hardware
- Basis: ISO 53 basic rack: 20° pressure angle, addendum m, dedendum 1.25 m; pitch Ø = m × teeth, tip Ø = m × (teeth + 2), root Ø = m × (teeth − 2.5)
- Page: https://xemstudio.com/objects/spur-gears-module-0-5/ · JSON: https://xemstudio.com/api/geometry?object=spur-gears-module-0-5 · Plain text: https://xemstudio.com/objects/spur-gears-module-0-5/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses
- 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

- Centre distance of two module 0.5 gears = m × (N1 + N2) / 2. Face width 4 mm, plain bore (add a hub, key or set screw to suit). Teeth below 17 are drawn without profile shift, so they undercut as real unshifted gears do.

## Sizes

| teeth | pitch_dia_mm | tip_dia_mm | root_dia_mm | face_mm | bore_mm |
|---|---|---|---|---|---|
| 10 | 5.0 | 6.0 | 3.75 | 4.0 | 1.5 |
| 12 | 6.0 | 7.0 | 4.75 | 4.0 | 2.0 |
| 14 | 7.0 | 8.0 | 5.75 | 4.0 | 2.0 |
| 15 | 7.5 | 8.5 | 6.25 | 4.0 | 2.0 |
| 16 | 8.0 | 9.0 | 6.75 | 4.0 | 2.0 |
| 18 | 9.0 | 10.0 | 7.75 | 4.0 | 3 |
| 20 | 10.0 | 11.0 | 8.75 | 4.0 | 3 |
| 22 | 11.0 | 12.0 | 9.75 | 4.0 | 3 |
| 24 | 12.0 | 13.0 | 10.75 | 4.0 | 4 |
| 25 | 12.5 | 13.5 | 11.25 | 4.0 | 4 |
| 28 | 14.0 | 15.0 | 12.75 | 4.0 | 4 |
| 30 | 15.0 | 16.0 | 13.75 | 4.0 | 5 |
| 32 | 16.0 | 17.0 | 14.75 | 4.0 | 5 |
| 35 | 17.5 | 18.5 | 16.25 | 4.0 | 6 |
| 36 | 18.0 | 19.0 | 16.75 | 4.0 | 6 |
| 40 | 20.0 | 21.0 | 18.75 | 4.0 | 7 |
| 42 | 21.0 | 22.0 | 19.75 | 4.0 | 7 |
| 45 | 22.5 | 23.5 | 21.25 | 4.0 | 7 |
| 48 | 24.0 | 25.0 | 22.75 | 4.0 | 8 |
| 50 | 25.0 | 26.0 | 23.75 | 4.0 | 8 |
| 56 | 28.0 | 29.0 | 26.75 | 4.0 | 9 |
| 60 | 30.0 | 31.0 | 28.75 | 4.0 | 10 |
| 64 | 32.0 | 33.0 | 30.75 | 4.0 | 11 |
| 70 | 35.0 | 36.0 | 33.75 | 4.0 | 12 |
| 72 | 36.0 | 37.0 | 34.75 | 4.0 | 12 |
| 80 | 40.0 | 41.0 | 38.75 | 4.0 | 14 |

## Where the files are

- ISO: [ISO 53 standard basic rack (20° pressure angle, addendum 1 m, dedendum 1.25 m) and ISO 54 modules](https://www.iso.org/standard/5768.html) — standard — ISO; dimensions are facts (verify at link)

## Free STEP/STL (26 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/spur-gears-module-0-5/index.json

- gear-m0-5-10t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-10t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-10t.stl) — module 0.5, 10 teeth: pitch Ø5, tip Ø6, root Ø3.75, face 4, bore Ø1.5
- gear-m0-5-12t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-12t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-12t.stl) — module 0.5, 12 teeth: pitch Ø6, tip Ø7, root Ø4.75, face 4, bore Ø2
- gear-m0-5-14t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-14t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-14t.stl) — module 0.5, 14 teeth: pitch Ø7, tip Ø8, root Ø5.75, face 4, bore Ø2
- gear-m0-5-15t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-15t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-15t.stl) — module 0.5, 15 teeth: pitch Ø7.5, tip Ø8.5, root Ø6.25, face 4, bore Ø2
- gear-m0-5-16t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-16t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-16t.stl) — module 0.5, 16 teeth: pitch Ø8, tip Ø9, root Ø6.75, face 4, bore Ø2
- gear-m0-5-18t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-18t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-18t.stl) — module 0.5, 18 teeth: pitch Ø9, tip Ø10, root Ø7.75, face 4, bore Ø3
- gear-m0-5-20t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-20t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-20t.stl) — module 0.5, 20 teeth: pitch Ø10, tip Ø11, root Ø8.75, face 4, bore Ø3
- gear-m0-5-22t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-22t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-22t.stl) — module 0.5, 22 teeth: pitch Ø11, tip Ø12, root Ø9.75, face 4, bore Ø3
- gear-m0-5-24t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-24t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-24t.stl) — module 0.5, 24 teeth: pitch Ø12, tip Ø13, root Ø10.75, face 4, bore Ø4
- gear-m0-5-25t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-25t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-25t.stl) — module 0.5, 25 teeth: pitch Ø12.5, tip Ø13.5, root Ø11.25, face 4, bore Ø4
- gear-m0-5-28t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-28t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-28t.stl) — module 0.5, 28 teeth: pitch Ø14, tip Ø15, root Ø12.75, face 4, bore Ø4
- gear-m0-5-30t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-30t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-30t.stl) — module 0.5, 30 teeth: pitch Ø15, tip Ø16, root Ø13.75, face 4, bore Ø5
- gear-m0-5-32t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-32t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-32t.stl) — module 0.5, 32 teeth: pitch Ø16, tip Ø17, root Ø14.75, face 4, bore Ø5
- gear-m0-5-35t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-35t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-35t.stl) — module 0.5, 35 teeth: pitch Ø17.5, tip Ø18.5, root Ø16.25, face 4, bore Ø6
- gear-m0-5-36t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-36t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-36t.stl) — module 0.5, 36 teeth: pitch Ø18, tip Ø19, root Ø16.75, face 4, bore Ø6
- gear-m0-5-40t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-40t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-40t.stl) — module 0.5, 40 teeth: pitch Ø20, tip Ø21, root Ø18.75, face 4, bore Ø7
- gear-m0-5-42t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-42t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-42t.stl) — module 0.5, 42 teeth: pitch Ø21, tip Ø22, root Ø19.75, face 4, bore Ø7
- gear-m0-5-45t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-45t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-45t.stl) — module 0.5, 45 teeth: pitch Ø22.5, tip Ø23.5, root Ø21.25, face 4, bore Ø7
- gear-m0-5-48t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-48t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-48t.stl) — module 0.5, 48 teeth: pitch Ø24, tip Ø25, root Ø22.75, face 4, bore Ø8
- gear-m0-5-50t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-50t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-50t.stl) — module 0.5, 50 teeth: pitch Ø25, tip Ø26, root Ø23.75, face 4, bore Ø8
- gear-m0-5-56t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-56t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-56t.stl) — module 0.5, 56 teeth: pitch Ø28, tip Ø29, root Ø26.75, face 4, bore Ø9
- gear-m0-5-60t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-60t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-60t.stl) — module 0.5, 60 teeth: pitch Ø30, tip Ø31, root Ø28.75, face 4, bore Ø10
- gear-m0-5-64t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-64t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-64t.stl) — module 0.5, 64 teeth: pitch Ø32, tip Ø33, root Ø30.75, face 4, bore Ø11
- gear-m0-5-70t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-70t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-70t.stl) — module 0.5, 70 teeth: pitch Ø35, tip Ø36, root Ø33.75, face 4, bore Ø12
- gear-m0-5-72t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-72t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-72t.stl) — module 0.5, 72 teeth: pitch Ø36, tip Ø37, root Ø34.75, face 4, bore Ø12
- gear-m0-5-80t: [STEP](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-80t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-module-0-5/gear-m0-5-80t.stl) — module 0.5, 80 teeth: pitch Ø40, tip Ø41, root Ø38.75, face 4, bore Ø14

## Questions

**Pitch diameter of a module 0.5, 20-tooth gear?**

10 mm; tip 11 mm.

**Centre distance?**

m × (N1 + N2) / 2: a 20 and a 40 tooth module 0.5 pair sit 15 mm apart.

## Fits with

- [Spur gears, module 0.8: 10 to 80 teeth (20° involute)](https://xemstudio.com/objects/spur-gears-module-0-8/)
- [Spur gears, module 1: 10 to 80 teeth (20° involute)](https://xemstudio.com/objects/spur-gears-module-1/)
- [Spur gears, module 1.25: 10 to 80 teeth (20° involute)](https://xemstudio.com/objects/spur-gears-module-1-25/)
- [Spur gears, module 1.5: 10 to 80 teeth (20° involute)](https://xemstudio.com/objects/spur-gears-module-1-5/)
- [Spur gears, module 2: 10 to 80 teeth (20° involute)](https://xemstudio.com/objects/spur-gears-module-2/)
- [Spur gears, involute 20°: module 0.5, 1 and 2, 12–60 teeth](https://xemstudio.com/objects/spur-gears-involute/)