HIWIN MGN12H miniature linear guide block: 27 × 45.4 body, M3 20 × 20 holes and rail interface — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/hiwin-mgn12h-linear-guide-block/  (sheet CC BY 4.0)
Basis: HIWIN Linear Guideway catalogue, MGN series tables for the MGN12 block and MGNR12R rail.
Catalog version: 2026-10-20

Overall (mm): length 45.4, width 27.0, height 10.0
- Datum: block centre; block underside at 0, top mounting face at 10.0. In assembly the underside is H1 3.0 above the rail bottom and the top face H 13.0 above it.
- Block width W 27.0, overall length L 45.4 including end caps and seals (steel body L1 32.4).
- Four M3 × 3.5 deep tapped holes in the top face on B × C = 20 × 20, centred on the block (modelled Ø2.5 tap drill).
- Underside rail channel 12.0 wide × 5.0 tall along the full length. Mating rail MGNR12R: width 12, height 8.0, M3 cap screws in Ø6.0 × 4.5 counterbores with Ø3.5 through holes at pitch 25.
- Not modelled: end-seal and end-cap profile, the Ø2 lube hole, ball grooves and retainer, and the rail.
- Dimensions are exact nominal (true size), no tolerance added.

hole  x (mm)  y (mm)  thread
1  −10.0  −10.0  M3 × 3.5
2  +10.0  −10.0  M3 × 3.5
3  −10.0  +10.0  M3 × 3.5
4  +10.0  +10.0  M3 × 3.5

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- HIWIN (catalogue via DAMENCNC): HIWIN MGN and MGW Product Catalog 2023 — web — Publisher's page; dimensions are facts — https://damencnc.com/userdata/file/3455-3_HIWIN_MGN_and_MGW_Product_Catalog_2023.pdf
- HIWIN (catalogue via Motion USA): HIWIN MG Series 2025 — web — Publisher's page; dimensions are facts — https://s3.amazonaws.com/www.motionusa.com/hiwin/2025/MG%20Series-2025.pdf

Free files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/hiwin-mgn12h-linear-guide-block/index.json
API: https://xemstudio.com/api/geometry?object=hiwin-mgn12h-linear-guide-block