MGN12C / MGN12H Miniature Linear Guide — Standard & Extended Length Blocks
The MGN12 is the most common miniature guide size, used on 3D printer gantries, laser cutters and desktop CNC conversions. MGN12C is the standard block; MGN12H is the extended block for cantilevered heads that need more moment capacity on the same MGN R12 rail.
Specifications
| Model | MGN12C / MGN12H |
| Size | 12 mm |
| Block type | Miniature, standard (C) / extended (H) |
| Mounting | Top tapped |
| Accuracy grade | C / H / P |
| Preload | ZF / Z0 / Z1 |
| Matching rail | MGN R12 |
| Dynamic load C (kgf, C / H) | 290 / 380 |
| Static load C0 (kgf, C / H) | 400 / 600 |
| Block height H (mm) | 13 |
| Block width W (mm) | 27 |
| Block length L (mm) | 34.7 (C) / 45.4 (H) |
Complete dimension table (mm) — MGN12C / MGN12H
| H | 13 |
| H1 | 3 |
| N | 7.5 |
| W | 27 |
| B | 20 |
| B1 | 3.5 |
| C block length | 15 |
| L1 | 21.7 (C) / 32.4 (H) |
| L | 34.7 (C) / 45.4 (H) |
| G | — |
| Gn | Ø1.4 |
| M | M3x3.5 |
| H2 | 2.5 |
| Wr | 12 |
| Hr | 8 |
| D | 6 |
| h | 4.5 |
| d | 3.5 |
| P | 25 |
| E | 10 |
| Rail bolt | M3x8 |
| Dynamic C | 290 / 380 kgf (2.84 / 3.73 kN) |
| Static C0 | 400 / 600 kgf (3.92 / 5.88 kN) |
| MR | 2.6 / 3.9 kN-m |
| MP | 1.4 / 3.7 kN-m |
| MY | 1.4 / 3.7 kN-m |
| Block weight | 34 / 54 g |
| Rail weight | 0.65 kg/m |
Transcribed from the current product catalogue. 2D drawing and STEP model on request.
Options
- Block length: standard (C) or extended (H)
- Dust protection on request
- Stainless steel version on request
- Special rail lengths on request
Where this block is used
Miniature blocks are used where moving mass has to stay small: 3D printer gantries, laser heads, dispensing axes and small pick-and-place slides. The C and H blocks share one rail, so an axis can be rebuilt with more moment capacity without changing the rail or the hole pattern.
Mounting: rails and blocks are bolted to machined faces. Rail bolts are tightened from the centre outwards in the sequence given in the catalogue, and running accuracy is checked with a dial gauge before the carriage is loaded. Lubrication is by grease nipple or oil port; the re-greasing interval follows load and duty cycle, so it is agreed with the customer rather than fixed on the datasheet.
Matching rail
MGN R12 rail is cut to order from 100 mm. See rail options.
Downloads
STEP (AP214) model and 2D drawing for this size are available on request — ask us and we will email them.
FAQ
| What is the difference between MGN12C and MGN12H? | C is the standard block, H is the extended block. The H block is longer and carries a higher moment load; both use the same MGN R12 rail. |
| Does MGN12H mean heavy load? | No. On the MGN series the H suffix means extended length, not heavy load. Load capacity is set by the 12 mm size. |
| Which accuracy and preload are available? | Accuracy C / H / P and preload ZF / Z0 / Z1. SP and UP are not offered on MGN. |
| Are the load ratings in kgf or kN? | The catalogue prints this series in kgf (1 kgf = 9.81 N). For MGN15C that is 470 kgf ≈ 4.6 kN. Ask for the signed datasheet if you need the value confirmed in kN. |