# MGN9 / MGN12 / MGN15 miniature linear rails and carriages

> What are MGN12H carriage dimensions and mounting holes?

- Category: Hardware › Motion
- Kind: Hardware
- Basis: HIWIN MGN series catalogue dimensions (rail profile, hole pitch, carriage envelope and mounting pattern); other brands match
- Page: https://xemstudio.com/objects/mgn-linear-rails/ · JSON: https://xemstudio.com/api/geometry?object=mgn-linear-rails · Plain text: https://xemstudio.com/objects/mgn-linear-rails/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses

## Notes

- Rail: MGN9 9 × 6.5 mm with 20 mm hole pitch; MGN12 12 × 8 mm, 25 mm pitch; MGN15 15 × 10 mm, 40 mm pitch. Holes Ø3.5 with Ø6 counterbore for M3.
- Carriage (H = long, C = short): MGN12H 45.4 × 27 × 13 mm assembled height, M3 holes on 20 × 20; MGN12C 34.7 long, holes 20 × 15. MGN9H 38.4 × 20 × 10, holes 15 × 20.
- Mount rails to a flat reference; printed mounts need the counterbores modeled (Ø6.2 × 4.5) so the M3 heads sit below the rail top.

## Sizes

| part | length_mm | width_mm | height_mm | holes | pitch_or_pattern_mm |
|---|---|---|---|---|---|
| MGN9 rail | 150–400 | 9 | 6.5 | Ø3.5 cbore Ø6 | 20 |
| MGN12 rail | 150–400 | 12 | 8 | Ø3.5 cbore Ø6 | 25 |
| MGN15 rail | 150–400 | 15 | 10 | Ø3.5 cbore Ø6 | 40 |
| MGN9C | 28.9 | 20 | 10 | 4 × M3 | 15 × 10 |
| MGN9H | 38.4 | 20 | 10 | 4 × M3 | 15 × 20 |
| MGN12C | 34.7 | 27 | 13 | 4 × M3 | 20 × 15 |
| MGN12H | 45.4 | 27 | 13 | 4 × M3 | 20 × 20 |
| MGN15H | 58.8 | 32 | 16 | 4 × M3 | 25 × 20 |

## Where the files are

- HIWIN: [MGN series linear guideway catalogue](https://www.hiwin.com/en/products/linear-guideways/mgn-mgw-series) — PDF, STEP — HIWIN site terms (verify at link)
- Wikipedia: [Linear-motion bearing](https://en.wikipedia.org/wiki/Linear-motion_bearing) — web — CC BY-SA 4.0 (text)

## Free STEP/STL (17 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/mgn-linear-rails/index.json

- mgn9-rail-150: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn9-rail-150.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn9-rail-150.stl) — MGN9 rail 150 mm, 20 mm hole pitch
- mgn9-rail-200: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn9-rail-200.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn9-rail-200.stl) — MGN9 rail 200 mm, 20 mm hole pitch
- mgn9-rail-300: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn9-rail-300.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn9-rail-300.stl) — MGN9 rail 300 mm, 20 mm hole pitch
- mgn9-rail-400: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn9-rail-400.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn9-rail-400.stl) — MGN9 rail 400 mm, 20 mm hole pitch
- mgn12-rail-150: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn12-rail-150.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn12-rail-150.stl) — MGN12 rail 150 mm, 25 mm hole pitch
- mgn12-rail-200: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn12-rail-200.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn12-rail-200.stl) — MGN12 rail 200 mm, 25 mm hole pitch
- mgn12-rail-300: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn12-rail-300.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn12-rail-300.stl) — MGN12 rail 300 mm, 25 mm hole pitch
- mgn12-rail-400: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn12-rail-400.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn12-rail-400.stl) — MGN12 rail 400 mm, 25 mm hole pitch
- mgn15-rail-150: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn15-rail-150.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn15-rail-150.stl) — MGN15 rail 150 mm, 40 mm hole pitch
- mgn15-rail-200: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn15-rail-200.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn15-rail-200.stl) — MGN15 rail 200 mm, 40 mm hole pitch
- mgn15-rail-300: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn15-rail-300.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn15-rail-300.stl) — MGN15 rail 300 mm, 40 mm hole pitch
- mgn15-rail-400: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn15-rail-400.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn15-rail-400.stl) — MGN15 rail 400 mm, 40 mm hole pitch
- mgn9h-carriage: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn9h-carriage.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn9h-carriage.stl) — MGN9H carriage envelope, 15 × 20 mm M3 pattern
- mgn9c-carriage: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn9c-carriage.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn9c-carriage.stl) — MGN9C carriage envelope, 15 × 10 mm M3 pattern
- mgn12h-carriage: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn12h-carriage.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn12h-carriage.stl) — MGN12H carriage envelope, 20 × 20 mm M3 pattern
- mgn12c-carriage: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn12c-carriage.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn12c-carriage.stl) — MGN12C carriage envelope, 20 × 15 mm M3 pattern
- mgn15h-carriage: [STEP](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn15h-carriage.step) · [STL](https://xemstudio.com/files/hardware/mgn-linear-rails/mgn15h-carriage.stl) — MGN15H carriage envelope, 25 × 20 mm M3 pattern

## Questions

**What are MGN12H carriage dimensions?**

45.4 mm long, 27 mm wide, 13 mm high from the rail bottom; four M3 holes on a 20 × 20 mm pattern.

**What is the hole spacing on an MGN12 rail?**

25 mm pitch, Ø3.5 holes with a Ø6 counterbore 4.5 deep, for M3 socket screws. MGN9 is 20 mm pitch, MGN15 is 40.

**MGN12C vs MGN12H?**

Same width and height; C is the short block (34.7 mm, holes 20 × 15), H is the long block (45.4 mm, holes 20 × 20) with more load capacity.

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