DFH 440c Linear Rails

440C stainless MGN rails for printer and small-CNC motion. DFH 440C Linear Rails are miniature linear guide rails with matching carriages, stocked across MGN7H, MGN9C, MGN9H, MGN12H, MGN15H, and selected MGN15C dual-carriage formats with Z0, Z1, or selected Z2 preload options.

Why pick 440C rails?

• Corrosion-resistant 440C stainless steel is a better fit for humid shops, enclosed printers, and machines that may sit between jobs than plain carbon-steel rails.
• MGN-format rolling guideways give compact, low-friction linear motion for 3D printers, CoreXY gantries, beds, probes, fixtures, and small CNC or mill projects.
• Preload options let you tune the axis: choose easy motion for lightly loaded axes or more constraint where stiffness matters.

Choose the right preload

• Z0: light preload and the easiest hand feel. Use for Z axes, bed motion, Ender-style conversions, and low-load axes unless your BOM specifies otherwise.
• Z1: more constraint than Z0. Good for X/Y gantries, CoreXY motion, toolheads, and general printer motion where stiffness matters more than free-fall feel.
• Z2: higher preload on selected variants only. Use when the build needs extra stiffness or support; expect a noticeably tighter feel before grease and break-in.

Specifications

• Series stocked: MGN7H, MGN9C, MGN9H, MGN12H, MGN15H, and selected MGN15C dual-carriage rails.
• Lengths stocked: 50mm through 500mm depending on selected rail type.
• Material: 440C stainless steel linear rail assembly.
• Preload: Z0, Z1, and selected Z2 options.
• Sold by selected variant: standard MGN variants are rail + carriage; MGN15C Dual Carriage variants include the second carriage.
• Preparation: rails may arrive with light storage oil or EP2 grease depending on batch. Wipe, inspect, and grease before final service.

Fitment notes

Use the exact rail type, length, preload, and carriage count from your project BOM. These rails are commonly used in Voron, CoreXY, Ender-conversion, fixture, and compact CNC builds, but a rail that is close is not always interchangeable.

If you want a project-specific rail bundle instead of loose rails, see the live DFH 440C Salad Fork 160mm Linear Rails Kit, BeltDrivenEnder3 440C Stainless Steel Linear Rails Kit, or Zero G Mercury One.1 Linear Rails Kit.

Gotchas before you install

• Higher preload will not free-fall. Z1 and Z2 rails often feel tight by hand, especially before grease and real machine load.
• Do not cut unless you know the process. If you must shorten a rail, use an abrasive method with shallow passes and control heat to avoid warping.
• This is not a full motion kit. Order belts, pulleys, idlers, fasteners, and project plates separately unless your BOM only calls for the rail itself.

“Super smooth” — verified buyer