Description

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The DLY MD miniature linear guide is a compact recirculating ball guideway developed for precision equipment where installation height, moving weight and mounting space are limited. Its Gothic-arch raceways support loads from four directions while maintaining smooth, stable linear motion.

The series includes the narrow MDN miniature linear guide and the wide MDW miniature linear guide. Both are available with C standard-length blocks and H long blocks in sizes 7, 9, 12 and 15. Rail length, block quantity, accuracy grade, preload and mounting configuration can be confirmed according to the machine design.

For other rail sizes and structural options, view the complete linear guideway range.

Series MDN narrow type / MDW wide type

Available Sizes 7, 9, 12 and 15

Block Length C standard / H long

MOQ 1 piece

Product Features

Compact construction: low assembly height and lightweight blocks suit instruments and small automation mechanisms.
Four-direction loading: Gothic-arch raceways provide rigidity against loads from the upper, lower and lateral directions.
Two width options: MDN reduces occupied width, while MDW provides a wider mounting surface and improved moment stability.
Standard and long blocks: C blocks save length; H blocks offer higher load and moment capacity within the same rail size.
Ball-retainer design: available specifications retain the balls when the block is removed from the rail, simplifying installation and maintenance.
Flexible specification: rail length, block quantity, accuracy grade and preload can be selected for the operating condition.

MDN Narrow Type

MDN is the standard narrow version of the MD miniature linear guide. Its slim rail and block reduce the space required across the mounting surface, making it suitable for compact mechanisms arranged close to adjacent components.

MDN miniature linear guide construction and ball circulation system

Item	MDN 7	MDN 9	MDN 12	MDN 15
Assembly height H	8 mm	10 mm	13 mm	16 mm
Block width W	17 mm	20 mm	27 mm	32 mm
Rail width WR	7 mm	9 mm	12 mm	15 mm
C block length L	22.5 mm	28.9 mm	34.7 mm	42.1 mm
H block length L	30.8 mm	39.9 mm	45.4 mm	58.8 mm
Rail mounting pitch P	15 mm	20 mm	25 mm	40 mm

MDN lubrication: sizes 7, 9 and 12 are lubricated through the side hole in the end cap; MDN 15 can be supplied with a grease nipple. End seals, optional bottom seals and mounting-hole caps are available according to size.

MDW Wide Type

MDW uses a wider rail and block than the corresponding MDN size. The increased mounting width improves resistance to rolling moments and provides a more stable platform where the moving component has a wide base, offset load or limited space for a two-rail arrangement.

MDW wide miniature linear guide construction and ball circulation system

Item	MDW 7	MDW 9	MDW 12	MDW 15
Assembly height H	9 mm	12 mm	14 mm	16 mm
Block width W	25 mm	30 mm	40 mm	60 mm
Rail width WR	14 mm	18 mm	24 mm	42 mm
C block length L	31.2 mm	39.3 mm	46.1 mm	54.8 mm
H block length L	41 mm	50.7 mm	60.4 mm	73.8 mm
Rail mounting pitch P	30 mm	30 mm	40 mm	40 mm

MDW sizes 7, 9 and 12 use a lubrication hole in the end cap. MDW 15 can be fitted with a grease nipple. Sealing and rail-hole cap options depend on the selected size and mounting arrangement.

Model Selection

Option	Construction	Selection Priority
MDN-C	Narrow rail with standard block	Minimum width and short installation length
MDN-H	Narrow rail with long block	Narrow layout with increased load and moment capacity
MDW-C	Wide rail with standard block	Wide mounting platform with moderate block length
MDW-H	Wide rail with long block	Higher stability for offset loads and moment loading

MDN narrow square miniature linear guide block types

MDN-C and MDN-H Narrow Blocks

MDW wide miniature linear guide block types

MDW-C and MDW-H Wide Blocks

Accuracy and Preload

Accuracy and preload should be selected according to positioning requirements, installation accuracy, operating load and required running resistance. Higher accuracy cannot compensate for an uneven mounting surface, so the rail seat and block mounting surfaces should be machined and aligned before assembly.

Category	Code	Description	Typical Use
Accuracy	C	Normal grade	General compact automation
Accuracy	H	High grade	Measuring and positioning mechanisms
Accuracy	P	Precision grade	Higher-precision motion systems
Preload	ZF	Light clearance, approximately 4–10 μm	Low running resistance and smooth manual motion
Preload	Z0	Very light preload	Balanced rigidity and running resistance
Preload	Z1	Light preload	Higher rigidity where installation accuracy is controlled

Rail Mounting

MD rails can be configured for mounting from the top or from the bottom. Confirm the mounting direction, screw size, rail-hole arrangement and available tool clearance before ordering.

Mounting from the Top

Mounting from the Bottom

Dimensions

The drawings below identify the principal dimensions for the MDN and MDW C/H blocks. When requesting a quotation, provide the series, size, block length, rail length, block quantity and mounting configuration.

MDW C and H wide miniature linear guide dimensions

Applications

Electronics Equipment PCB handling, inspection stages and compact assembly mechanisms.

Measuring Instruments Sensor positioning, optical adjustment and laboratory motion devices.

Medical Equipment Compact sample handling, inspection and instrument adjustment mechanisms.

Small Automation Pick-and-place units, miniature modules and precision transfer devices.

Ordering Information

To confirm the correct miniature linear guide, please provide:

MDN narrow type or MDW wide type
Size 7, 9, 12 or 15
C standard block or H long block
Required rail length and number of blocks per rail
Accuracy grade and preload requirement
Top or bottom rail mounting configuration
Operating load, speed, stroke and installation drawing

FAQ

Q: What is the difference between MDN and MDW?

A: MDN has a narrow rail and block for installations with limited width. MDW uses a wider rail and mounting platform, providing better resistance to moment loading and greater stability under offset loads.

Q: What is the difference between C and H blocks?

A: C is the standard-length block and is preferred when installation length must be minimized. H is the long block, with more load-carrying balls and generally higher load and moment capacity.

Q: Can the rail length and block quantity be customized?

A: Yes. Rail length, mounting-hole arrangement and the number of blocks on each rail can be confirmed according to the installation drawing and stroke requirement.

Q: Can a block be removed from the rail?

A: Specifications equipped with a ball retainer help prevent the balls from falling when the block is removed. Even so, use a transfer rail where possible and avoid rotating or forcing the block during removal.

Q: What information is required for model replacement?

A: Provide the current model, assembly height, rail width, mounting-hole pitch, block dimensions, rail length, accuracy grade and preload. A drawing or clear dimensional photo is recommended before confirming interchangeability.