MGN7 MGN9 MGN12 MGN15 440C Linear Guide Rail & Block for CNC

Kande MGN Series 440C Stainless Steel Linear Guide Rail & Carriage Block

Upgrade your CNC machine or 3D printer with precision-engineered MGN linear guide rails and carriage blocks from Kande Bearings. Crafted from high-grade SUS440C martensitic stainless steel, these miniature linear guides deliver smooth, accurate, and repeatable motion — making them the ideal choice for desktop CNC routers, 3D printers, laser engravers, and other precision motion applications.

Available in four popular widths — MGN7, MGN9, MGN12, and MGN15 — and in rail lengths from 100mm to 800mm, you can configure the perfect linear motion system for your build.

What's Included

• 1 Set = 1 MGN Guide Rail + 1 MGN Carriage Block (H or C type)
• If you select a single block option (1 MGN12C or 1 MGN12H), you will receive 1 carriage block only — the guide rail is not included in single-block orders.

Key Features

• Material: SUS440C stainless steel for both rail and slider — offering excellent corrosion resistance and durability
• Models Available: MGN7, MGN9, MGN12, MGN15
• Rail Lengths: 100mm – 800mm (select your preferred length)
• Block Types: MGN12H (long block) / MGN12C (standard block)
• Class C Precision: Rail and slider are matched to Class C tolerance for consistent performance
• Preload Options:
  • ZF (Normal Clearance): Slider moves freely under its own weight when vertical — ideal for most 3D printers and light desktop devices
  • Z0 (No Preload): Moves under light applied thrust — suitable for general desktop CNC use
  • Z1 (Light Preload): Higher stiffness for applications requiring greater accuracy and longer service life
• Also Available: Nickel-plated, chrome-plated, and blackened rail finishes — contact us for custom options

Preload Selection Guide

We recommend ZF or Z0 preload for most 3D printers and light desktop machines. Z1 preload is best reserved for precision applications where tighter tolerances and extended service life are critical. Z0/ZA variants are shipped randomly at the same price unless otherwise specified.

Important Note: Additional replacement steel balls are not included with this kit. Due to tight manufacturing tolerances (ranging from –4μ to +2μ), using mismatched steel balls can reduce carriage block service life. We do not recommend substituting the factory steel balls.

Made in Mainland China.

Compatible Applications

• FDM and resin 3D printers (Voron, Ender series upgrades, custom builds)
• Desktop CNC routers and laser engravers
• DIY automation and robotics projects
• Camera sliders and linear actuator systems
• Light industrial pick-and-place equipment

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Frequently Asked Questions

Q: What is the difference between MGN12H and MGN12C carriage blocks?

A: The MGN12H is a long carriage block that provides greater contact area with the rail, offering higher load capacity and improved rigidity — ideal for heavier toolheads or gantry assemblies. The MGN12C is a standard-length carriage block that is more compact and better suited for lightweight applications like 3D printer toolheads where minimizing moving mass is important.

Q: Which MGN size should I choose for my 3D printer or CNC machine?

A: MGN7 is best for very lightweight, compact printer axes. MGN9 is popular for mid-size 3D printer X/Y axes. MGN12 is the most widely used size across 3D printers and small CNC machines, striking an excellent balance between size and rigidity. MGN15 is suited for larger, heavier gantry systems and desktop CNC routers requiring greater load-bearing capacity.

Q: Do these linear guides come pre-lubricated?

A: The guides are shipped without liquid lubricants (air transport restrictions prevent the inclusion of oil-based lubricants). We recommend applying a suitable machine grease or light machine oil to the rail and carriage ball circuit before first use and periodically thereafter to ensure smooth operation and long service life.

Q: Can I order just the carriage block without the rail?

A: Yes. If you select the single-block option (e.g., 1 MGN12C or 1 MGN12H), your order will include 1 carriage block only — the guide rail is not included. If you need both the rail and the block, please select the full set option (1 set = 1 guide rail + 1 carriage block).

Production & Packaging Notice

To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.