Linear Guide Interchange Chart: HIWIN, THK, PMI, TBI, ABBA and CPC Compared

October 2026 11 min read Selection Guide

Searches for a linear guide “equivalent” almost always start from the same fact: the square-block HG and flange HGW footprints, the low-assembly EG sizes and the MGN / MGW miniature range are the most widely copied dimension families in the linear motion market. That is good news — but it is a statement about mounting geometry, not about performance, and treating it as the latter is how substitution projects go wrong.

This page sets out what genuinely carries over between makers for each RFU Motion guide family, then gives you the seven checks that decide whether a substitute really fits. We would rather hand you a checklist than a table of model numbers we cannot stand behind.

Read this before replacing anything

Wherever a designation is called shared, that refers to mounting dimensions only — bore, width, height and bolt hole pattern. It never means mixing one maker’s running element into another maker’s raceway, and it never guarantees equal load rating or preload. Confirm against the current dimension drawing before ordering.

Our range at a glance

The table below states, for every RFU Motion family, whether the designation itself is shared across the industry or is our own house code. That single distinction decides how the rest of the page applies to you.

RFU Motion	Construction	Size range	What carries over between makers
HGH..CA / HA	Square block, heavy load, 4-row ball	15–45	The high-assembly square-block footprint is the most widely copied in the industry. Many makers list a same-size square block, but block length, preload code and load rating differ.	Shared code
HGW..CA / HA	Flange block, heavy load, 4-row ball	15–45	Flange variant of the same family. Hole pattern on the flange face is the usual difference between makers.	Shared code
EGH / EGW..SA / CA	Low assembly height, 4-row ball	15–35	Low-assembly footprints are also widely copied, though the exact assembly height can vary by a fraction of a millimetre.	Shared code
RGH / RGW..CA / HA	Roller type, ultra-high rigidity	15–65	Roller guides are less standardised than ball guides: roller pitch, block length and stiffness ratings vary significantly. Treat any roller-guide swap as a drawing check, not a code match.	Shared code
MGN / MGW	Miniature guideway, ball type	7–15	The miniature footprint is widely copied and usually the easiest family to substitute — provided load and preload are re-checked at the smaller scale.	Shared code

What carries over between makers — and what does not

Shared code The designation itself is used across the industry. Bore and mounting form carry over; hole centres, height and load rating still need checking.

House code RFU Motion’s own designation. There is no cross-brand model to quote — match by drawing and we will confirm the part.

The 7-point check before you substitute

Run all seven before ordering anything. If any one of them fails, the part will fit the rail but not the machine.

Rail mounting hole pitch and diameter — measure centre-to-centre along the rail and the hole diameter; both vary between makers even in a copied family.
Assembly height H — from the rail mounting face to the top of the block, at nominal dimension and tolerance.
Block length, width and lock-pin position — block length is the dimension most often overlooked; it changes the end-seal positions and the effective stroke.
Dynamic load rating C and static C0 — compare against your actual load, not against the old part’s number alone.
Preload class — Z0 (clearance), ZA (light) and ZB (medium) are common but not universal labels — confirm what the old block actually ran.
Accuracy class — C, H, P or higher; a copied footprint does not imply a copied grade.
Seals and lubrication — end seals, side seals, seal kit options and grease nipple position on the block.

When you should not substitute

Roller for ball, or ball for roller. A roller guide will not drop into a ball-guide application: stiffness, moment capacity and running behaviour differ fundamentally.
Matched pairs on a shared bed. Where two rails run under one cross member, both must be replaced as an equal-height matched set — mixing makers breaks the height grading.
High-preload or precision-grade positions. The higher the preload and grade, the less a same-size part from another maker behaves the same.
Any position with special seals, scrapers or lubrication kits. These options are maker-specific and rarely swap over.

Which family does your guide belong to

If your block is a tall square carriage with four ball rows, start from HGH..CA / HA. A flange-shaped carriage that bolts through its base plate belongs to HGW..CA / HA. A noticeably shorter carriage is the EG low-assembly family, and pencil-thin rails under 15 mm are MGN / MGW. Roller carriages are visibly longer for the same width and belong to RGH / RGW..CA / HA. Photograph the old part and send us the stamped marking — we will place it in the right family for you.

Send us the old part number or a dimension drawing — we will run the check with you and quote from the standard range, or machine to drawing where a standard part will not do.

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Back to the cross reference overview

HIWIN, THK, PMI, TBI MOTION, ABBA, CPC, NSK, IKO, NB, SBC and Bosch Rexroth are trademarks of their respective owners. Brand names on this page identify dimension families only and do not imply endorsement, affiliation or authorised replacement status.