MGN9 / MGN12 / MGN15 miniature linear rails and carriages — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/mgn-linear-rails/  (CC BY 4.0)
Basis: HIWIN MGN series catalogue dimensions (rail profile, hole pitch, carriage envelope and mounting pattern); other brands match
Catalog version: 2026-10-20

Sizes: see table below
- 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.

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

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- HIWIN: MGN series linear guideway catalogue — PDF, STEP — HIWIN site terms [verify license at link] — https://www.hiwin.com/en/products/linear-guideways/mgn-mgw-series
- Wikipedia: Linear-motion bearing — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Linear-motion_bearing

Free files (CC BY 4.0, Xem Studio; STEP + STL, 17 parts): https://xemstudio.com/files/hardware/mgn-linear-rails/index.json
API: https://xemstudio.com/api/geometry?object=mgn-linear-rails