MGN Series Linear Guideway — MGN3,MGN5,MGN7, MGN9, MGN12 & MGN15 Miniature Guide Rails

MGN Series Linear Guideway — MGN3,MGN5,MGN7, MGN9, MGN12 & MGN15 Miniature Guide Rails

MGN series linear guideway is a miniature linear guide rail system built around a four-row ball circulation block running on a compact profile rail. The name encodes the design: M for miniature — rail widths run from 2 mm to 15 mm — and G for the ball-type rolling element. Because the balls are arranged symmetrically inside the block, an MGN guideway carries equal load in all four directions (radial, reverse radial and both lateral) while keeping a very low mounting height. That combination is why this miniature linear guideway is the default choice for semiconductor handling, SMT pick-and-place, 3D printing, medical instrumentation and precision inspection equipment, where every millimetre of height matters.

KGT manufactures the full MGN range — MGN3, MGN5, MGN7, MGN9, MGN12 and MGN15 — in C, H and P accuracy grades, with stainless steel variants for wet or cleanroom environments. Rails are cut to length and machined to your drawing at our ISO 9001 certified factory in Wenzhou, Zhejiang. See the miniature linear guideway range for the complete family, or request a quote with your drawing for a 24-hour reply.

What Is an MGN Series Linear Guideway?

An MGN guideway consists of two parts: a hardened profile rail with precision-ground raceways, and a block that recirculates steel balls through a four-point contact groove. As the block travels, the balls roll rather than slide, so friction stays low, stick-slip disappears and positioning repeatability improves — the three reasons ball-type miniature linear rails replaced sliding guides in compact automation.

Three design details separate an MGN series linear guideway from a generic linear rail:

• Four-direction equal load. The four rows of balls are preloaded against the raceway at 45°, so the block resists downward, upward and both side loads with the same stiffness. A machine builder can mount the rail in any orientation without re-rating the block.
• Low sectional height. An MGN block is shorter than a heavy-duty HGH block of the same width, which lets designers stack axes closer together in multi-axis heads.
• Matched block and rail. Blocks and rails are supplied as matched sets for the ordered accuracy grade, and replacement blocks can be quoted against the original rail model number, which shortens maintenance downtime.

If your design needs more moment capacity than a narrow block gives, the MGW wide miniature linear guideway uses the same rail platform with a wider, longer block. If the axis carries machine-tool level loads, move up to the HGH heavy-load linear guideway.

MGN Model Naming: MGN7, MGN9, MGN12 and MGN15

Every MGN part number can be read position by position. The table below decodes the convention so you can specify the right block on the first enquiry instead of the third.

The most common sizes in automation are MGN7, MGN9, MGN12 and MGN15. MGN7 and MGN9 suit the smallest heads — piezo stages, optical mounts, lab dispensers. MGN12 is the workhorse size for SMT nozzles, 3D printer X/Y axes and small gantries. MGN15 is chosen when the same footprint has to carry a heavier head or a longer cantilever. Adding the H suffix gives a longer block with a higher load rating on the same rail: MGN12H carries 3.72 kN against 2.84 kN for the standard MGN12C block.

Technical Specifications

The table below lists the standard MGN range with catalogue load ratings per block. Dynamic load C is the rating used for life calculation; static load C0 and static rated moment MR are the values to check against shock loads and cantilevered mounting. Full dimensional drawings with block and rail dimensions are available on request.

Reading the table. Moving one size up buys more capacity than most engineers expect: MGN9C is roughly twice the dynamic rating of MGN5C (1.86 kN against 0.54 kN), while MGN12H at 3.72 kN is only 30 % above MGN12C but twice its moment rating (38.22 against 25.48 N·m). When a design is deflection-limited rather than load-limited, the H block usually solves it without going to a wider rail.

Rail length. Rails are cut and machined to your drawing — send the required length, mounting hole pitch and end details, and we return a machining check with the quotation.

Accuracy Grades, Preload and Clearance

Accuracy grade and preload are two independent choices, and mixing them up is the most common specification error we see. Accuracy grade controls how far the block deviates from a perfect straight line as it travels along the rail — it is a geometric tolerance. Preload controls how tightly the balls are squeezed between block and rail — it is a stiffness setting.

KGT supplies MGN guideways in three accuracy grades: standard (C), high (H) and precision (P). Higher grades tighten running parallelism and height tolerance, which matters when two rails run in parallel on the same gantry or when the axis feeds a measuring probe. Standard grade is sufficient for pick-and-place and general automation where the position is closed by a servo and encoder.

Note that the accuracy letter is not the block letter: MGN12H is a long block in standard precision unless a grade is specified, and the grade is written separately on the order. Preload is set per order — tell us whether the axis runs continuously at high speed (a small clearance keeps temperature rise down) or must hold position under vibration (light preload removes internal play), and we confirm the class that matches.

Typical Applications for MGN Miniature Guide Rails

MGN series linear guideway models appear wherever an axis must be short, light and precise at the same time. The five application groups below cover most of the enquiries we quote.

Semiconductor and electronics manufacturing

Die bonders, wire bonders, wafer handling robots and probe stations use MGN9 and MGN12 for the fine-positioning axes. Stainless variants are common in front-end tools where humidity and chemical exposure rule out coated carbon steel.

SMT and PCB assembly

Pick-and-place heads, dispensers and AOI cameras run MGN12 and MGN15 on gantries that must accelerate quickly without overshoot. The four-direction equal load rating lets the head be mounted in either orientation without re-rating the block.

3D printing and additive manufacturing

Cartesian printers use MGN12 for X and Y and MGN15 for the heavier bed axis. Low friction keeps motor torque small and reduces ringing artifacts at high print speeds.

Medical, laboratory and analytical instruments

Sample handlers, syringe pumps, microscope stages and IVD analyzers choose MGN7 and MGN9 for their small sectional height. Stainless rails and cleanroom lubricant are specified when the instrument sits in a controlled environment.

Inspection, measurement and general automation

CMM fixtures, vision measuring machines, laser markers and small assembly cells combine MGN12 rails with a ball screw axis. The engineer's guide to miniature linear rails walks through a full axis design, and our application library collects the multi-axis positioning cases we have built for customers.

Materials and Surface Treatment

Standard MGN series linear guideway rails and blocks are made from through-hardened bearing steel, ground and finished to the specified accuracy grade. This is the highest-rigidity option and covers most industrial automation.

Stainless steel versions are specified for semiconductor front-end tools, medical analyzers, food and packaging lines and any application with wash-down or condensing humidity. The trade-off is a lower load rating, so confirm the stainless figures before downsizing the rail.

For cleanroom and vacuum applications, ask about low-outgassing lubricant and hole-free rail ends. Our applications team can also advise on bellows or telescopic covers where dust ingress is the dominant wear factor.

Customization: Rail Length, Hole Pitch and End Machining

Most MGN series linear guideway projects need something that is not in the catalogue. We machine rails to drawing and ship matched block-and-rail sets, so the accuracy grade you specify is the grade you receive.

Send the drawing as PDF, DWG or STEP. We return a machining check and quotation within 24 hours, and we flag any dimension that cannot be produced at the requested accuracy grade before you place the order.

Quality Control and Inspection

Every MGN series linear guideway batch is produced in an ISO 9001 certified plant in Wenzhou, Zhejiang, with inspection at four points: incoming steel, raceway grinding, block assembly and final packing. Running parallelism, height tolerance and clearance are verified against the ordered accuracy grade before the blocks are matched to their rails.

Each shipment includes a dimensional inspection report matched to the rail model numbers. If your quality system requires it, we can add material certificates, hardness records or a first-article inspection report before dispatch — tell us at the quotation stage rather than after production.

How Ordering Works

MOQ and lead time are not fixed numbers across the range: a standard MGN12C rail and a stainless MGN15S with custom end machining are quoted on completely different terms. Sending the drawing with the enquiry is what makes the 24-hour quotation accurate.

Frequently Asked Questions

What does MGN stand for in linear guides?

MGN is the model prefix for KGT's miniature linear guideway range: M stands for miniature and G for the ball-type rolling element. The number that follows is the rail width in millimetres, so an MGN12 rides a 12 mm wide rail. A trailing C marks the standard block and H the longer block; an S suffix marks stainless steel.

What is the difference between MGN and MGW miniature guides?

Both series ride the same miniature rail platform. MGN uses a narrow standard block, which is the most compact option. MGW uses a wider and longer block that resists higher moment loads, making it the better choice when a single rail carries an offset or cantilevered head. For a comparison at equal rail width, MGW gives more moment capacity at the cost of some extra width.

Which accuracy grade and preload should I choose?

We supply standard (C), high (H) and precision (P) accuracy grades; preload is set per order. Choose a higher accuracy grade when two rails run in parallel or when the axis feeds a measuring probe — standard grade is enough for servo-driven pick-and-place. Tell us the running speed and whether the axis must hold under vibration, and we confirm the preload class.

Can you supply custom rail lengths and machined ends?

Yes. Rails are cut to the length on your drawing, with end tapping, mounting hole pitch and joint marking machined to your specification. Send a 2D drawing or STEP model and we return a machining check and quotation within 24 hours, including any dimension that cannot meet the requested accuracy grade.

What is the MOQ and lead time for MGN guideways?

Both depend on size, accuracy grade and how much customization is involved, so they are quoted together with the price rather than published as fixed numbers. A standard MGN12C rail and a custom stainless MGN15 are quoted on different terms — send the drawing and we confirm MOQ and lead time within 24 hours.

Do you provide datasheets, 3D models and inspection reports?

Yes. The dimensional drawing for the model you need, STEP models for design review and a dimensional inspection report matched to the rail model numbers are available. Request them through the quote form or by email and we will send the files for your current rail size.

Request an MGN Series Quote

Send the rail length, block quantity, accuracy grade and any end-machining requirement. We reply with price, MOQ, lead time and a drawing check within 24 hours, and we tell you upfront if the tolerance you need is not achievable at the grade you selected.

Request a quote or datasheet · Whatsapp +8618715778888 · or send your drawing to our applications team and we will recommend the size.