MGN12C Miniature Linear Guide Block — 12 mm, Standard Length
The MGN12C is the standard-length block of the MGN12 size: 34.7 mm long, 13 mm high, 27 mm wide, rated 2.84 kN dynamic and 3.92 kN static. It runs on the MGN R12 rail and shares that rail with the extended MGN12H block, so a machine designed around one can switch to the other without changing the rail.
Mounting envelope: H 13 mm × W 27 mm × L 34.7 mm. Bolt spacing and rail hole pitch: see the dimension table below.
Specifications
| Model | MGN12C |
| Size | 12 mm |
| Block type | Miniature, standard length (C) |
| Mounting | Top tapped |
| Accuracy grade | C / H / P |
| Preload | ZF (C grade only) / Z0 / Z1 (0.02C) |
| Matching rail | MGN R12 |
| Dynamic load C (kgf / kN) | 290 kgf (2.84 kN) |
| Static load C0 (kgf / kN) | 400 kgf (3.92 kN) |
| Block height H (mm) | 13 |
| Block width W (mm) | 27 |
| Block length L (mm) | 34.7 |
| Block weight | 34 g |
Accuracy C / H / P. Preload ZF (C grade only, 4–10 µm clearance) / Z0 / Z1 (0.02C).
Source: Yuantong product manual, MGN dimension table, p.68 (printed page 62). Loads are printed in kgf in that table and converted at 1 kgf = 9.81 N. Accuracy per manual p.64 (printed 58); preload per p.65 (printed 59), Table 2.51. Checked against our model data at build time.
Options
- Stainless steel rail (M code) on request
- Dust plate +U available at 9, 12 and 15 mm
- 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, shortest length confirmed with each quotation. See rail options.
Where this size is used
At 12 mm the guide is used on printer gantries, laser heads, dispensing axes and small pick-and-place slides, where the moving mass has to stay low and the stroke is usually under a metre. The same size is also common on bench-top routers and inspection stages.
Mounting details for this size
All blocks in this family
The family shares one rail bolt pattern per size, so a machine designed around one block can move to another form without re-machining the rail. The table lists every model we publish in this family, with the size and the rated dynamic load.
| Model | Size | Type | C |
|---|---|---|---|
| MGN12C / MGN12H | 12 mm | Miniature block (standard C / extended H) | — |
| MGW12C / MGW12H | 12 mm | Wide miniature block | — |
| MGN15C / MGN15H | 15 mm | Miniature block (standard C / extended H) | — |
| MGW15C / MGW15H | 15 mm | Wide miniature block | — |
| MGN7C / MGN7H | 7 mm | Miniature block (standard C / extended H) | — |
| MGW7C / MGW7H | 7 mm | Wide miniature block | — |
| MGN9C / MGN9H | 9 mm | Miniature block (standard C / extended H) | — |
| MGW9C / MGW9H | 9 mm | Wide miniature block | — |
All models we publish, with sizes and load ratings, are on the linear guide blocks index; the rail side is on the rail index.
The other block of the same size
MGN12H runs on the same MGN R12 rail at the same 13 mm height and 27 mm width. It is 45.4 mm long against 34.7 mm here, so the mounting face does not change — only the load rating and the travel the block costs at the end stops.
MGN12H · MGN12 series page · MGN12C vs MGN12H: full comparison
Same size, other block types
The three block types share the rail for a given size but differ in height, footprint and how the carriage is bolted down. If the mounting height is fixed, compare H first; if the carriage plate is thin, compare W and the bolt pattern; if the frame cannot be raised, the low-profile block is the one to look at.
| Model | H (mm) | W (mm) | L (mm) | C (kN) | Rail |
|---|---|---|---|---|---|
| MGN12C / MGN12H | 13 | 27 | 34.7 (C) / 45.4 (H) | — | MGN R12 |
Check before you order
- Look up the 12 size on the replacement tool and confirm the dimensions against your drawing.
- Choosing between body types? See narrow or wide miniature guide.
- Fitting it, or unsure about preload? Read how to select the size.
Choosing this size
Three numbers decide whether this size is right: the load per block, the moment from an overhanging load, and the stroke. Work out the load first: if the carriage carries more than a third of the rated dynamic load C in normal operation, go one size up rather than increase preload. Preload does not raise the load rating; it only removes clearance, and over-preloading a light axis adds friction and heat for no gain.
For a horizontal axis with the load centred, ZA is usually enough. ZB is for a vertical axis, a cantilever, or a machine where the cutting force reverses direction; it is supplied as a matched set. Accuracy follows the machine, not the other way round: C for general automation, H for machine tools with a hand-scraped bed, P where the axis is measured against a straight edge. SP and UP are for grinding and measuring machines, and they come as a lapped block-and-rail set.
What to send with an enquiry
- Model and quantity, or the size if the model is still open.
- Accuracy grade and preload, or the application if you want us to recommend one.
- For rails: stroke, number of holes, or the centre distance between the end holes.
- Mounting orientation and the load on the carriage, if the axis is unusual.
- A drawing if you have one; if not, the four items above are enough to quote.
Quotations are made against the exact configuration, not a catalogue price. The reply states the model, the accuracy and preload, the rail length and the lead time for that combination, so the comparison with another supplier is on the same basis.
Downloads
STEP (AP214) model and 2D drawing for this size are available on request — ask us and we will email them.
FAQ
| Is MGN12C the standard or the extended block? | Standard. The C suffix is the shorter body: 34.7 mm against 45.4 mm for MGN12H. Both run on the MGN R12 rail. |
| Can I replace an MGN12H with an MGN12C? | On the same rail, yes — but check the end stops and the load. The C block is 10.7 mm shorter and rated 2.84 kN against 3.73 kN. |
| Which rail does it use? | MGN R12. Hole pitch P = 25 mm, end distance E = 10 mm. |