ISO 19457:2026

International
Standard
ISO 19457
First edition
Rolling bearings — Roller blocks
2026-07
as subassemblies for linear motion
rolling bearings — Boundary
dimensions and tolerance values
Roulements — Roulements pour mouvement linéaire, sous-
ensembles, patin à rouleaux — Dimensions d'encombrement et
valeurs de tolérance
Reference number
© ISO 2026
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 4
5 Designs and types . 5
6 Boundary dimensions . 7
7 Tolerance values . 9
Annex A (informative) Roller block Type E and roller block Type F .11
Annex B (informative) Configurations of roller blocks . 14
Annex C (informative) Recommendations on adjacent mounting surfaces .15
Bibliography .16

iii
Foreword
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This document was prepared by Technical Committee ISO/TC 4, Rolling bearings, Subcommittee SC 11,
Linear motion rolling bearings.
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iv
Introduction
Linear motion rolling bearing subassemblies as standardized in this document are a product that has been
on the market for several decades. It is projected that these products will become less important in future
technology. However, in some application areas there is still a need for spare parts.
The designs with profiled rail guides and linear motion rolling bearings in ISO 12090-1 and ISO 12090-2 can
replace the roller block design given in this document.
The title of this document applies the classification of linear motion rolling bearings as defined in
ISO 24393:2008, Annex A.
v
International Standard ISO 19457:2026(en)
Rolling bearings — Roller blocks as subassemblies for
linear motion rolling bearings — Boundary dimensions and
tolerance values
1 Scope
This document specifies the boundary dimensions and tolerances for Types A to D of roller blocks.
Types E and F of roller blocks are given in Annex A. They require fixing parts and are not yet produced on a
broad manufacturer base.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 15241, Rolling bearings — Symbols for physical quantities
ISO 24393:2008, Rolling bearings — Linear motion rolling bearings — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 24393:2008 and the following
apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
roller block
linear roller bearing
linear bearing subassembly consisting of roller block body and a number of closed loops of recirculating
rollers, which are designed to achieve unlimited motion along a flat rail or flat guideway
Note 1 to entry: An example of a roller block is illustrated in Figure 1.
[SOURCE: ISO 24393:2008, 03.01.07]

Key
1 roller block body (3.2)
2 rollers
3 roller holding part (3.3)
Figure 1 — Example of a roller block with exploded view
3.2
roller block body
cuboid part having rectangular cross-section of a roller block with one or more raceways on one of its
outside surfaces and supporting load
Note 1 to entry: See Figure 1.
[SOURCE: ISO 24393:2008, 04.01.07 modified – The wordings “having rectangular cross-section” as well as
“and supporting load” have been added. "basically" has been removed.]
3.3
roller holding part
parts of roller block except rollers and roller block body which together retain and guide the rollers in a
recirculation path
Note 1 to entry: See Figure 1.
3.4
mounting surface
surface of the roller block which is fixed to the adjacent construction
Note 1 to entry: See Figure 2.
a) Roller block Type A
b) Roller block Type B
c) Roller block Type C
d) Roller block Type D
e) Roller block Type E
f) Roller block Type F
Key
1 mounting surface
Figure 2 — Mounting surfaces of roller blocks
3.5
rolling surface
plane theoretically tangential to the cylindrical surfaces of rollers
Note 1 to entry: See Figure 3.

Key
1 rolling surface
Figure 3 — Rolling surface
4 Symbols
For the purposes of this document, the symbols given in ISO 15241 and the following apply, see Table 1.
The symbols (except those for tolerances) shown in Figures 4 to 7 and the values given in Tables 2 to 6
denote nominal dimensions, unless specified otherwise.
Table 1 — Symbols
Symbol Description Unit
B Overall width of roller block mm
B Width of roller holding part mm
H Height from mounting surface to rolling surface mm
H Height of roller block mm
h Overall length of bolt hole mm
h Height of mounting flange mm
J Centre distance between mounting bolt holes (width) mm
J Centre distance between mounting bolt holes (length) mm
L Length of roller block mm
L Length of mounting flange mm
L Length of mounting surface mm
M Designation of internal screw thread for mounting bolts -
N Diameter of mounting bolt holes mm
a, b
V Variation of the sorting height µm
HmL
V Variation of height from mounting surface to rolling surface µm
Hs
∆
Deviation of overall width of roller block µm
Bs
∆ Deviation of width of roller holding p
...