DLY vs HIWIN Linear Guides: Model and Dimension Comparison

When replacing an existing linear guide or evaluating a second supply source, engineers often begin by comparing model codes and basic assembly dimensions. DLY HD, ED, MD and RD linear guideways correspond broadly to the product categories represented by HIWIN HG, EG, MG and RG series.

However, a similar series designation or nominal size does not automatically make two linear guides fully interchangeable. Rail width, assembly height and block width provide a useful starting point, but mounting-hole positions, block length, rail-hole pitch, accuracy, preload, seals and load ratings must also be checked.

The following DLY linear guide vs HIWIN comparison retains the original model reference table while adding the technical checks required before a replacement is approved.

Series Comparison

HD and ED use recirculating balls, while RD uses rollers. A roller guide should not be selected as a direct substitute for a ball guide solely because the nominal rail size is the same. Rolling-element type affects rigidity, friction, load response and installation requirements.

DLY and HIWIN Model Comparison Table

The table below compares model families, nominal sizes, combined assembly height and block width. "Medium load" and "heavy load" identify the block-length or load-class variants within the same basic series.

HD and HG Heavy-Load Ball Guides

DLY HD and HIWIN HG belong to the general heavy-load ball linear guide category. Both square blocks and flange blocks are represented in the comparison table.

DLY uses HDH for the narrower square-block form and HDW for the wider flange-block form. The square type is suitable for narrower mounting platforms, while the flange type provides a wider mounting surface and additional installation options.

DLY HD heavy-load ball linear guideway

The HD series is suitable for machining equipment, CNC routers, automation systems, cutting machines and other equipment requiring balanced load capacity and rigidity. View the DLY HD square guideway for detailed DLY specifications.

ED and EG Low-Profile Ball Guides

DLY ED and HIWIN EG are low-profile ball guideway families. Their reduced assembly height makes them suitable for equipment where the distance between the machine base and moving platform is limited.

DLY EDH identifies the square-block form, while EDW identifies the wider flange-block form. A low-profile guide should not be confused with a miniature guide. ED reduces the assembly height while retaining industrial rail sizes from 15 to 30; MD is intended for much smaller instruments and compact mechanisms.

DLY ED low-profile ball guideway sizes

Typical applications include packaging machinery, woodworking equipment, semiconductor auxiliary equipment, inspection systems and compact automation axes.

MD and MG Miniature Guides

DLY MD and HIWIN MG are miniature ball linear guideway families. The narrow MDN form minimizes installation width, while the wider MDW form provides a broader base and greater resistance to moment loads within a compact assembly.

When evaluating an MG-to-MD replacement, check more than the nominal size. Miniature systems are particularly sensitive to rail-hole pitch, block mounting-thread size, block length and installation-surface accuracy because the available assembly space is limited.

The MD series is generally used in inspection instruments, laboratory automation, compact handling equipment, small electronic machinery and other lightweight precision-motion systems. Detailed dimensions are available on the DLY MD miniature linear guide page.

RD and RG Roller Guides

DLY RD and HIWIN RG belong to the roller linear guide category. Rollers create line contact with the raceways, while ball guideways create point-type contact that develops into an elliptical contact area under load. The roller arrangement generally provides higher rigidity and lower elastic deformation under heavy loading.

DLY RD high-rigidity roller linear guide block

RD roller guides are intended for machine tools, machining centers, grinding machines, injection-molding equipment and other machinery where structural rigidity and load resistance are more important than selecting the lowest-friction guide type.

Because roller guides respond more strongly to mounting errors and structural deformation, the rail seats, reference shoulders, parallelism and tightening sequence must be controlled carefully.

What Must Match Before Replacement?

The model comparison table narrows the range of possible DLY equivalents. The following items must then be verified using the drawings and technical data for both products.

Can a DLY Block Run on an Existing HIWIN Rail?

Replacing only the block while retaining a rail from another manufacturer is not recommended solely on the basis of nominal size. Even when a block can physically be installed, differences in raceway geometry, ball or roller dimensions, preload control and manufacturing tolerances may affect clearance, friction and load distribution.

The safer replacement method is to use a matched DLY rail-and-block assembly. If an application requires block-only replacement, provide the complete existing model, rail cross-section, accuracy grade and preload information for engineering review and sample verification.

When Is DLY a Suitable Alternative?

DLY linear guideways can be evaluated when an OEM, distributor or maintenance team needs:

• A second supply source for standard linear guide sizes
• Matched rail-and-block assemblies for new equipment
• Rails cut to a required length
• Custom rail-hole positions or end distances
• Different block quantities on one rail
• Application-based preload and accuracy selection
• Batch supply for machinery and automation projects

The comparison should be based on the operating requirement rather than price alone. Load, moment, speed, stroke, mounting accuracy, contamination and expected service life should be reviewed before the final DLY model is confirmed.

Information Needed for Model Matching

For an accurate cross-reference, send DLY the complete existing model code and available technical information. Useful details include:

• Complete guide and block model number
• Rail length and required quantity
• Number of blocks per rail
• Accuracy and preload requirements
• Rail-hole pitch and end-hole distances
• Operating load, speed and stroke
• Machine type and installation orientation
• Drawings or photographs of the existing assembly

DLY can compare these requirements with the HD, ED, MD or RD series and provide a drawing for confirmation before production.

Conclusion

DLY HD, ED, MD and RD guideways provide practical model references for users evaluating alternatives to HG, EG, MG and RG series linear guides. The comparison table helps identify a possible DLY series and nominal size, but it is only the first stage of replacement evaluation.

Before changing suppliers, verify the complete installation dimensions, load ratings, accuracy, preload, sealing arrangement and operating conditions. For existing machines, replacing the rail and blocks as a matched assembly generally provides a more controlled result than mixing components from different manufacturers.

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