EN 12080:2017+A1:2022

SLOVENSKI STANDARD
01-november-2022
Železniške naprave - Ohišja ležajev kolesnih dvojic - Kotalni ležaji (vključno z
dopolnilom A1)
Railway applications - Axleboxes - Rolling bearings
Bahnanwendungen - Radsatzlager - Wälzlager
Applications ferroviaires - Boîtes d'essieux - Roulements
Ta slovenski standard je istoveten z: EN 12080:2017+A1:2022
ICS:
21.100.20 Kotalni ležaji Rolling bearings
45.040 Materiali in deli za železniško Materials and components
tehniko for railway engineering
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12080:2017+A1
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2022
EUROPÄISCHE NORM
ICS 21.100.20; 45.040 Supersedes EN 12080:2017
English Version
Railway applications - Axleboxes - Rolling bearings
Applications ferroviaires - Boîtes d'essieux - Bahnanwendungen - Radsatzlager - Wälzlager
Roulements
This European Standard was approved by CEN on 19 June 2017 and includes Amendment 1 approved by CEN on 6 June 2022.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12080:2017+A1:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 5
Introduction . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Technical specification . 11
4.1 General requirements . 11
4.2 Technical specification content . 11
5 Quality systems . 12
6 Manufacture . 12
6.1 Steel manufacturing . 12
6.2 Heat treatment . 12
6.3 Traceability . 13
6.4 Coatings . 14
6.4.1 General . 14
6.4.2 Permanent coating. 14
6.4.3 Non-permanent coating . 14
7 Material properties . 14
7.1 General . 14
7.2 Steel for rings and rolling elements . 14
7.2.1 Grades. 14
7.2.2 Inclusion content . 15
7.3 Materials of other components (cages, spacers, seals etc.) . 15
8 Geometry and dimensions . 15
8.1 Dimensions and tolerances . 15
8.2 Rolling bearing internal clearance . 15
8.2.1 Rolling bearing clearance before mounting . 15
8.2.2 Rolling bearing clearance after mounting . 16
9 Mechanical properties — inner ring expanding ability . 16
10 Physical properties . 16
10.1 Visual aspect . 16
10.1.1 Rings and rolling elements . 16
10.1.2 Cages . 16
10.2 Soundness of rings and rolling elements . 16
10.2.1 General rules . 16
10.2.2 Internal soundness of rings . 17
10.2.3 Soundness of ring surfaces . 17
10.2.4 Soundness of roller raceway surfaces . 17
10.2.5 Grinding burns . 17
10.3 Case depth . 17
10.4 Surface hardness . 18
11 Marking . 18
11.1 General . 18
11.2 Marking of rings for cylindrical roller bearings (CRB) . 19
11.3 Marking of cartridge bearings for axleboxes. 19
11.4 Marking of spherical roller bearings (SRB) . 20
11.5 Prefix and postfix . 20
12 Inspection . 20
12.1 Inspection plan . 20
12.2 Sampling . 21
13 Quality records . 22
14 Approval . 22
15 Delivery and packing . 22
15.1 Greasing of rolling bearings . 22
15.2 Corrosion protection . 22
15.3 Packaging . 22
Annex A (normative) Ultrasonic inspection of rolling bearing rings . 24
A.1 Purpose . 24
A.2 Principle . 24
A.3 Equipment . 24
A.4 Operating procedure . 24
A.4.1 General rules . 24
A.4.2 Preparation of rings . 24
A.4.3 Examination . 25
A.4.4 Calibration . 25
Annex B (normative) Magnetic particle inspection of ring surfaces . 29
B.1 Purpose . 29
B.2 Principle . 29
B.3 Equipment . 29
B.4 Operation procedure . 30
B.4.1 Preparation of rings . 30
B.4.2 Examination . 30
B.4.3 Demagnetisation . 30
Annex C (normative) Eddy current inspection of the raceways of the rollers . 31
C.1 Purpose . 31
C.2 Principle . 31
C.3 Equipment . 31
C.4 Operating procedure . 31
C.4.1 Preparation of rollers . 31
C.4.2 Examination . 31
C.4.3 Calibration . 32
Annex D (normative) Cages of polymeric material . 34
D.1 Purpose . 34
D.2 Material . 34
D.2.1 General . 34
D.2.2 Base material . 34
D.2.3 Additives . 34
D.2.4 Conditioning . 34
D.3 Cage requirements . 34
D.3.1 Inspection plan. 34
D.3.2 Moisture content . 36
D.3.3 Fibre glass diameter and length measurement procedure . 36
D.3.4 Surface quality. 37
D.3.5 Sub-surface quality . 37
D.4 Mechanical tests . 39
D.4.1 Test conditions . 39
D.4.2 Bending test procedures . 40
D.4.3 Tension test procedures . 41
D.5 Thermal ageing in grease or oil bath . 43
Annex E (normative) Approval procedures . 44
E.1 General . 44
E.2 Complete procedure, type C . 44
E.2.1 General . 44
E.2.2 Stage 1 . 44
E.2.3 Stage 2 . 44
E.2.4 Stage 3 . 44
E.2.5 Stage 4 . 45
E.2.6 Decision . 45
E.3 Reduced procedure, type R . 45
Annex F (normative) Criteria to determine the extent of approval procedures . 46
Annex G (informative) Examples of axlebox assemblies . 48
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of Directive (EU) 2016/797 aimed to be covered . 50
Bibliography . 52

European foreword
This document (EN 12080:2017+A1:2022) has been prepared by Technical Committee CEN/TC 256
“Railway Applications”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2023, and conflicting national standards shall
be withdrawn at the latest by March 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document includes Amendment 1 approved by CEN on 6 June 2022.
This document supersedes !EN 12080:2017".
The start and finish of text introduced or altered by amendment is indicated in the text by tags !".
The main changes with respect to the previous edition are listed below:
— !The use of conditioning for polymer cages is no longer mandatory and is specified in 4.2
— A clarification of deviations in marking of cylindrical roller bearings is new in 11.2 and 11.3
— The inspection plan for inclusion content in 12.1 (footnote h in Table 3) has been made clearer and
now also includes specifications for sample preparations
— The sensor definition in C.3 is now more relevant
— Conditioning can now be performed also at the bearing manufacturer (see D.2.4)
— The sample frequency for polymeric cages in D.3.1.1 is now more relevant and the terms
“Approval” and “Series” are better defined
— Table D.1 has been renamed for clarity and the requirements for “Viscosity index” and “Length of
glass fibres” have been relaxed to be more relevant
— The requirement for “Mechanical test for material approval” in Table D.1 have been changed so that
it is clear that the Charpy impact test is on “un-notched” samples and made according to the
relevant norm, the requirement for the “Bending strength on the test specimen” is changed and a
clarification on how “Thermal ageing in grease or oil bath” is performed has been added
— Footnote d in Table D.1 now allows for use of inspection certificate 3.1 and a new footnote “h” is
added to specify sampling frequency
— ISO 15512 can be used for moisture content determination in D.3.2 and a clarification on the use of
desiccator is added
— In D.3.4.3 some additions are made on how to address burrs on the edge and outside of functional
areas
— D.3.5 is rewritten to address “void clusters” and Figure D.1 is replaced
— The Annex ZA has been revised to take into account EU Directive (EU) 2016/797"
This document has been prepared under a Standardization Request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of EU
Directive(s) / Regulation(s).
For relationship with EU Directive(s) / Regulation(s), see informative Annex ZA, which is an integral
part of this document.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
This standard is part of a set of standards: EN 12080, EN 12081 and EN 12082.
This European Standard has been drawn up with the purpose of aiming at optimum performance in rail
transportation. Performance implies a certain quality level of the vehicle running gear, which every
railway undertaking may require, notably by imposing procedures in approval and requesting the
existence of a quality assurance system for the supply of rolling bearings intended for rolling stock
operating on its network or other networks in Europe.
1 Scope
This European Standard specifies the quality parameters of axlebox rolling bearings supporting the load
of the vehicle, required for reliable operation of trains on European networks. It covers metallurgical
and material properties as well as geometric and dimensional characteristics. It also defines methods
for quality assurance and conditions for approval of the products.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN 10204:2004, Metallic products - Types of inspection documents
EN 12081:2017, Railway applications - Axleboxes - Lubricating greases
EN 12082:2017, Railway applications - Axleboxes - Performance testing
EN 13018:2016, Non-destructive testing - Visual testing - General principles
EN 15663:2017, Railway applications - Definition of vehicle reference masses
EN ISO 178:2010, Plastics - Determination of flexural properties (ISO 178:2010)
EN ISO 179-1:2010, Plastics - Determination of Charpy impact properties - Part 1: Non-instrumented
impact test (ISO 179-1:2010)
EN ISO 307:2007, Plastics - Polyamides - Determination of viscosity number (ISO 307:2007)
EN ISO 683-17:2014, Heat-treated steels, alloy steels and free-cutting steels - Part 17: Ball and roller
bearing steels (ISO 683-17:2014)
EN ISO 1172:2003, Textile-glass-reinforced plastics - Prepregs, moulding compounds and laminates -
Determination of the textile-glass and mineral-filler content - Calcination methods (ISO 1172:1996)
EN ISO 1183-1:2012, Plastics - Methods for determining the density of non-cellular plastics - Part 1:
Immersion method, liquid pyknometer method and titration method (ISO 1183-1:2012)
EN ISO 1183-2:2004, Plastics - Methods for determining the density of non-cellular plastics - Part 2:
Density gradient column method (ISO 1183-2:2004)
EN ISO 2639:2002, Steels - Determination and verification of the depth of carburized and hardened cases
(ISO 2639:2002)
EN ISO 3059:2012, Non-destructive testing - Penetrant testing and magnetic particle testing - Viewing
conditions (ISO 3059:2012)
EN ISO 3451-1:2008, Plastics - Determination of ash - Part 1: General methods (ISO 3451-1:2008)
EN ISO 6507-1:2005, Metallic materials - Vickers hardness test - Part 1: Test method (ISO 6507-1:2005)
EN ISO 6508-1:2016, Metallic materials - Rockwell hardness test - Part 1: Test method (ISO 6508-1:2016)
EN ISO 6508-2:2015, Metallic materials - Rockwell hardness test - Part 2: Verification and calibration of
testing machines and indenters (ISO 6508-2:2015)
EN ISO 6508-3:2015, Metallic materials - Rockwell hardness test - Part 3: Calibration of reference blocks
(ISO 6508-3:2015)
EN ISO 9934-1:2016, Non-destructive testing - Magnetic particle testing - Part 1: General principles
(ISO 9934-1:2016)
EN ISO 9934-2:2015, Non-destructive testing - Magnetic particle testing - Part 2: Detection media
(ISO 9934-2:2015)
EN ISO 9934-3:2014, Non-destructive testing - Magnetic particle testing - Part 3: Equipment
(ISO 9934-3:2015)
EN ISO 11357-3:2013, Plastics - Differential scanning calorimetry (DSC) - Part 3: Determination of
temperature and enthalpy of melting and crystallization (ISO 11357-3:2011)
ISO 281:2007, Rolling bearings — Dynamic load ratings and rating life
ISO 492:2014, Rolling bearings — Radial bearings — Geometrical product specifications (GPS) and
tolerance values
ISO 4967:2013, Steel - Determination of content of non-metallic inclusions - Micrographic method using
standard diagrams
!ISO 15512:2016, Plastics — Determination of water content"
ASTM E45:2014, Standard Test Methods for Determining the Inclusion Content of Steel
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply (see also Annex G for more
information).
3.1
customer
railway undertaking, rolling stock manufacturer, Entity in Charge of Maintenance (ECM) or buyer of
railway rolling stock or subassemblies, or their representative
3.2
railway undertaking
organization or its representative, whatever status it has, which is responsible for the registration of
rolling stock
3.3
manufacturer
manufacturer of axlebox rolling bearings produced under their responsibility
3.4
network
infrastructure, on which any railway undertaking can operate rolling stock
3.5
axlebox (assembly)
assembly consisting of the following major components: rolling bearing(s)/cartridge bearing, rolling
bearing grease, seal(s) and box housing
Note 1 to entry: Further components, e.g. bearing sleeve, housing cover(s), axle end cap components and
fasteners may also be part of the assembly. This depends on axlebox type and design (see Annex G).
3.6
bearing sleeve
component of box housing which contains rolling bearing(s), grease and sealing
3.7
housing cover
component which retains the bearing in the housing or bearing sleeve
3.8
axle end cap components
components which secure the rolling bearing axially on the journal
3.9
rolling bearing
bearing, operating with rolling motion between the parts supporting load and moving in relation to
each other
3.10
cartridge bearing
rolling bearing with two or more rows of rolling elements within a self-contained unit, greased and
equipped with integral seals
3.11
ring
annular part of a rolling bearing incorporating one or more raceways with rolling element contact
3.12
rolling elements
cylindrical, tapered or convex rollers or balls
3.13
cage
component, which partly surrounds the rolling elements and moves with them
3.14
grease
semi-solid lubricant, which consists of a thickener and additives dispersed in a lubricating oil
3.15
seal
component that protects the bearing(s) against ingress of water and dust and retains the grease in the
rolling bearing(s)
3.16
box housing
structural component which contains rolling bearing(s), seal(s) and grease
3.17
rolling bearing type
designation of the rolling bearing or cartridge bearing according to the shape of the rolling elements
(e.g. tapered roller bearing, cylindrical roller bearing, and spherical roller bearing)
3.18
rolling bearing design
designation of a specific rolling bearing or cartridge bearing design within a rolling bearing type (e. g.
WJ/WJP 130x240x80 P.C3), bearing design is a subset of a bearing type
3.19
ribs and thrust collars
annular component of a rolling bearing transmitting axial forces (separate from the bearing inner or
outer rings) in contact with the rolling element end face in cylindrical roller bearings
4 Technical specification
4.1 General requirements
The supply of a component or a service (rig tests, field test, calculations, etc.) shall be based on a
comprehensive specification. This specification shall consist of all the information relevant for design
and manufacture of the bearing describing the functional requirements over its complete life cycle and
the interfaces with associated components and assemblies.
The design and validation process requires the integration of different disciplines and areas of expertise
and the knowledge associated with them. Therefore, the specification shall include information defining
the intended operating conditions, calculation and test parameters.
The following information shall be part of the approval process and be fully documented in the
technical specification by either of the contracting parties. Both the requirements specified throughout
this European Standard and the following documented requirements shall be satisfied before a claim of
compliance with this European Standard can be made and verified.
4.2 Technical specification content
The technical specification shall contain at least the following information and requirements:
NOTE Usually the customer is responsible for items 1) to 6). Items 7) to 21) are usually subject to agreement
between contracting parties.
1) interface drawing showing mounting conditions; all dimensions of the space available for the
rolling bearings; dimensions, tolerances and materials of shaft and box housing;
2) load specification at least according to EN 12082;
3) ambient temperatures in operation;
4) if required, special steel composition, cleanliness and soundness class (see 7.1 and 10.2);
5) approval procedure type and conditions to be applied (see Clause 14 and Annex E);
6) special conditions for quality records and traceability (see 6.3 and Clause 13);
7) boundary dimensions and interface tolerances of the rolling bearing (see Clause 8);
8) type of coating and influence on boundary dimensions (see 6.4);
9) internal clearance measurement process and clearance values before and after mounting (see
Clause 8);
10) references to standards and special requirements (see Clause 7 and 10.2);
11) use of steel of special composition, manufacture or metallurgical quality (see 7.1);
12) soundness Class, 1 or 2, and the test methods to be used (see 10.2 and A.4.2);
13) type of heat treatment to be applied and methods of testing (see 6.2, 10.3, 10.4 and 12.2);
14) marking (see Clause 11);
15) inspection plan (see 12.1);
16) for cartridge bearings grease designation, quantity and distribution (see 15.1);
17) for non-sealed bearings, grease designation and compatibility with preservatives (see 15.2);
18) !selection of mechanical testing method for cages of polymeric material (see D.4.1) and selection
if conditioning shall be used or not for polymer cages (see D.2.4)"
19) material data sheet for polymer cage material;
20) proof of batch release according to EN 12081 for traceability;
21) method for determining steel cleanliness.
5 Quality systems
The quality of workmanship and manufacturing shall be demonstrated to ensure the requirements of
the technical specification are met.
NOTE 1 The manufacturer is responsible for this.
NOTE 2 Quality management system according to EN ISO 9001 is usually used.
NOTE 3 The system used for non-destructive testing staff is usually according to EN ISO 9712.
6 Manufacture
6.1 Steel manufacturing
The process of steel manufacture in mass production shall be such that the metallurgical characteristics
are the same as those of the rolling bearings submitted for the approval procedure.
6.2 Heat treatment
The heat treatment processes for the rolling bearing components shall be such that the hardness values
specified in 10.3 and/or 10.4 are respected. The heat treatment processes shall be such that all the
rolling bearings produced in a production batch are treated uniformly.
The bearings shall be heat-treated to retain dimensional stability for one of the two following
temperature categories:
— 150 °C
— 200 °C
The temperature category shall be given and documented in the Technical specification (Clause 4).
The bearings (inner and outer rings) shall be heat-treated to retain dimensional stability at least for
operating temperatures up to 150 °C.
Inner rings of cylindrical roller bearings that are heated during mounting or dismounting shall be
dimensionally stable up to 200 °C.
The retained austenite content for inner rings made of through-hardened rolling bearing steel must be:
— 150 °C: ≤ 3.0 % with a measuring accuracy of ± 1 %;
— 200 °C: ≤ 2.0 % with a measuring accuracy of ± 1 %.
For other steels, the retained austenite content must be defined in the course of the (type) approval
procedure.
The inspection frequency of the retained austenite content is specified in Table 3 — Inspection plan,
12.1. The method of measurement of retained austenite is to be defined in the technical specification
(Clause 4).
6.3 Traceability
For the manufacturing process a system of identification and traceability of finished products shall be
set up and maintained. This system shall allow identification, of the following elements:
— Raw material for rings and rollers;
— Inspection certificate 3.1 in accordance with EN 10204 or equivalent. Minimum content:
• !Chemical analysis (all elements having content limitations according to ISO 683-
17)";
• Steel production method;
• Microstructure (CN, CG, CZ);
• Inclusion content (see 7.2.2);
— Polymeric cages:
• Raw material (granulate material) + raw material manufacturer;
• Inspection results; inspections at least in accordance with EN 12080, Annex D;
• Manufacturer, manufacturer's mark, date of manufacture;
— Rolling bearing grease:
• Name, manufacturer !;"
• Inspection certificate 3.1 in accordance with EN 10204 or equivalent. The content of the
certificate is according to EN 12081.
— Production locations of rings and rollers;
— Traceability of heat treatment:
• Method;
• Temperature variations including nominal and actual values per heat treatment batch;
• Microstructural examination per heat treatment batch;
• Hardness values/case-hardening depth of rings and rollers in accordance with EN 12080,
Table 3;
• Retained austenite content, inspection frequency in accordance with 6.2;
• If there are several heat treatment batches per production batch they must be assignable to the
production batch;
— Significant changes in the finishing process after heat treatment that could lead to defects, e.g. so
called “grinding burns”;
— Traceability of the inspection results in accordance with the inspection plan, (see 12.1);
— Quality records in accordance with Clause 13 and records of inspection plans, inspection
instructions and calibrations.
6.4 Coatings
6.4.1 General
The type of coating used for the bearing boundary surfaces shall be agreed and documented in
accordance with Clause 4. Distinction shall be made between permanent coatings (e.g. for electrical
insulation) and non-permanent coatings (e.g. phosphate coating for corrosion protection).
6.4.2 Permanent coating
The dimensions in the finished state (including the coating) shall apply for approval and use of the
bearing.
6.4.3 Non-permanent coating
The dimensions before coating shall apply for approval and use of the bearing and the thickness of the
non-permanent coating shall be considered separately. Boundary dimensions shall be documented both
for the coated and the uncoated state.
7 Material properties
7.1 General
The grades and qualities of materials used shall conform to the requirements in 7.2 and 7.3.
7.2 Steel for rings and rolling elements
7.2.1 Grades
Steels should be selected from the grades specified in EN ISO 683-17. Alternative steel grades may be
used if specified in the technical specification. For particular applications (high rotational speed,
reliability etc.) it may be requested that the rolling bearings are made from steel with special
composition, metallurgical quality or manufacturing processes (Clause 4).
Additional requirements regarding the chemical composition (content in %) after the ladle analysis in
accordance with EN ISO 683-17 are listed below in Table 1 — Additional requirements, chemical
composition, through hardened steel and Table 2 — Additional requirements, chemical composition,
case carburised steel below.
Table 1 — Additional requirements, chemical composition, through hardened steel
Element Minimum Maximum
Ti 0 0.003
H 0 0.000 2
Table 2 — Additional requirements, chemical composition, case carburised steel
Element Minimum Maximum
Ti 0 0.005
H 0 0.000 25
7.2.2 Inclusion content
The methods for determining the inclusion content shall be in the technical specification.
The methods in accordance with ASTM E45 (Method A) and ISO 4967 (Method A) are permitted. For the
methods mentioned above, the limit values in accordance with EN ISO 683-17:2014, Annex A, Tables
A.1 and A.2 are authoritative.
The frequency and scope of inspection for inclusion content of raw material (bar, tube or billet) is
specified in Table 3 — Inspection plan, Clause 12.1).
When needed - inspection of single rings and rollers can also be made according to the methods and
requirements specified above providing enough samples are taken to form an average value.
NOTE ASTM E45 gives a recommendation for number of samples.
For steel with special composition, metallurgical quality or manufacturing processes, the inclusion
content shall be documented in accordance with Clause 4.
7.3 Materials of other components (cages, spacers, seals etc.)
The materials of each one of these components shall be documented in in the technical specification in
accordance with Clause 4. For cages of polymeric material, if not otherwise specified, refer to Annex D.
8 Geometry and dimensions
8.1 Dimensions and tolerances
The boundary dimensions shall be given in the technical specification, and the applicable tolerances
shall be those given in ISO 492, normal tolerance class, unless given and documented in the technical
specification in accordance with Clause 4.
8.2 Rolling bearing internal clearance
8.2.1 Rolling bearing clearance before mounting
Rolling bearing internal clearance, axial and/or radial, depending on the type of rolling bearing, shall
conform to the values given in the technical specification. The methods for radial and/or axial clearance
inspection shall be described and documented in the technical specification in accordance with
Clause 4.
8.2.2 Rolling bearing clearance after mounting
Rolling bearing clearance after mounting on an axle is a calculated value used for checking the clearance
after mounting. The values for clearance after mounting shall be described and documented by the
manufacturer in accordance with Clause 4.
9 Mechanical properties — inner ring expanding ability
With the exception of case-hardened rings and bainite hardened rings, an expansion test shall be
performed to guarantee that the inner rings can withstand an increase of the bore diameter without
causing fracture in service. This tes
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