SIST ISO 4378-2:2020

Plain bearings - Terms, definitions, classification and symbols - Part 2: Friction and wear

ISO 4378-2:2017 specifies the most commonly used terms relating to friction and wear of plain bearings with their definitions and classification.
For some terms and word combinations, their short forms are given, which can be used where they are unambiguous. Self-explanatory terms are given without definitions.

Paliers lisses - Termes, définitions, classification et symboles

L'ISO 4378-2:2017 spécifie les termes les plus couramment utilisés en matičre frottement et d'usure de paliers lisses, ainsi que leur définition et leur classification.
Les formes abrégées données pour certains termes peuvent ętre employées dans les cas oů elles ne créent aucune ambiguďté possible quant ŕ leur interprétation. Les termes suffisamment explicites par eux-męmes ne sont pas définis.

Drsni ležaji - Izrazi, definicije, klasifikacija in simboli - 2. del: Trenje in obraba

General Information

• Status: Published
• Publication Date: 10-Jun-2020
• ICS: 01.040.21 - Mechanical systems and components for general use (Vocabularies)
• ICS: 21.100.10 - Plain bearings
• Technical Committee: ISEL - Mechanical elements
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 09-Jun-2020
• Due Date: 14-Aug-2020
• Completion Date: 11-Jun-2020
• Ref Project: ISO 4378-2:2017 - Plain bearings — Terms, definitions, classification and symbols — Part 2: Friction and wear

Relations

• Revised: SIST ISO 4378-2:2015 - Plain bearings - Terms, definitions, classification and symbols - Part 2: Friction and wear
• Effective Date: 19-Dec-2015

Standards Content (Sample)

SLOVENSKI STANDARD
SIST ISO 4378-2:2020
01-september-2020
Drsni ležaji - Izrazi, definicije, klasifikacija in simboli - 2. del: Trenje in obraba
Plain bearings - Terms, definitions, classification and symbols - Part 2: Friction and wear
Paliers lisses - Termes, définitions, classification et symboles
Ta slovenski standard je istoveten z: ISO 4378-2:2017
ICS:
01.040.21 Mehanski sistemi in deli za Mechanical systems and
splošno rabo (Slovarji) components for general use
(Vocabularies)
21.100.10 Drsni ležaji Plain bearings
SIST ISO 4378-2:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ISO 4378-2:2020

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SIST ISO 4378-2:2020
INTERNATIONAL ISO
STANDARD 4378-2
Third edition
2017-07
Plain bearings — Terms, definitions,
classification and symbols —
Part 2:
Friction and wear
Paliers lisses — Termes, définitions, classification et symboles —
Partie 2: Frottement et usure
Reference number
ISO 4378-2:2017(E)
©
ISO 2017

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SIST ISO 4378-2:2020
ISO 4378-2:2017(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2017 – All rights reserved

---------------------- Page: 4 ----------------------
SIST ISO 4378-2:2020
ISO 4378-2:2017(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
© ISO 2017 – All rights reserved iii

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SIST ISO 4378-2:2020
ISO 4378-2:2017(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see the following
URL: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 123, Plain bearings, Subcommittee SC 6,
Terms and common items.
This third edition cancels and replaces the second edition (ISO 4378-2:2009), which has been technically
revised. The following changes have been made:
— editorial revision of the document;
— addition of 6 new figures;
— revision of clause numbers.
A list of all the parts in the ISO 4378 series can be found on the ISO website.
iv © ISO 2017 – All rights reserved

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SIST ISO 4378-2:2020
ISO 4378-2:2017(E)

Introduction
As there is a large number of multiple designations in the domain of plain bearings, there is a
considerable risk of error in the interpretation of standards and technical literature. This uncertainty
leads to the continuous addition of supplementary designations, which only serves to increase the
misunderstanding.
This document is an attempt to establish a uniform basic system of designations of friction and wear.
© ISO 2017 – All rights reserved v

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SIST ISO 4378-2:2020

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SIST ISO 4378-2:2020
INTERNATIONAL STANDARD ISO 4378-2:2017(E)
Plain bearings — Terms, definitions, classification and
symbols —
Part 2:
Friction and wear
1 Scope
This document specifies the most commonly used terms relating to friction and wear of plain bearings
with their definitions and classification.
For some terms and word combinations, their short forms are given, which can be used where they are
unambiguous. Self-explanatory terms are given without definitions.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1 General terms
3.1.1
external friction
force and its phenomenon of resistance to the relative motion between two bodies, originating at the
contact area of their surfaces and directed tangentially to them
3.1.2
internal friction
force and its phenomenon of resistance to the relative motion of particles or mass of a body with respect
to other particles or mass in the same body
© ISO 2017 – All rights reserved 1

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SIST ISO 4378-2:2020
ISO 4378-2:2017(E)

3.1.3
friction
force and its phenomenon of resistance to the relative motion working tangentially with respect to the
common boundary between two bodies when, under the action of an external force, one body moves or
is at rest relative to the surface of the other
Note 1 to entry: See Figure 1.
Key
W weight of material
P normal force
F friction force
Figure 1 — Friction
3.1.4
friction force
force due to friction (3.1.3)
Note 1 to entry: See Figure 1.
3.1.5
coefficient of friction
ratio of the friction force (3.1.4) between two bodies to the normal force pressing these bodies together
3.1.6
friction angle
angle, the tangent of which is equal to the ratio of the friction force (3.1.4) to the normal force, or
coefficient of friction (3.1.5)
Note 1 to entry: See Figure 1.
3.1.7
wear
process of wear or the result of a wear process (3.1.8)
3.1.8
wear process
process of a loss of substance from a solid body surface in frictional conditions, which appears as a
gradual decrease of body dimensions and/or change of shape
Note 1 to entry: Rarely, in a broader sense, is there a process of permanent increase of body dimensions on the
surface without loss of substance.
2 © ISO 2017 – All rights reserved

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SIST ISO 4378-2:2020
ISO 4378-2:2017(E)

3.1.9
wear rate
amount of wear (3.1.7) per unit sliding distance or per interval of time
Note 1 to entry: A distinction is made between “momentary” (at a definite moment) and “mean” wear rate (during
a definite interval of time).
3.1.10
specific wear rate
wear intensity
value of amount of wear (3.1.7) divided by the product of sliding distance (or time) and load; that is, the
ratio of wear rate (3.1.9) to the load
Note 1 to entry: Wear can be expressed in the units of length, volume, mass, etc.
Note 2 to entry: Wear intensity is distinguished as “momentary” or as “mean” wear intensity.
3.2 Types and characteristics of external friction and classification
3.2.1 Classification according to the presence of relative motion
3.2.1.1
static friction
friction (3.1.3) and its phenomena that occur between two contacting bodies before the start of relative
motion under increasing external force
Note 1 to entry: Friction that occurs at an extremely low sliding speed is also referred to as static friction.
Note 2 to entry: See Figure 2.
Key
f friction
L sliding distance
Figure 2 — Friction according to relative motion
3.2.1.2
maximum static friction
friction (3.1.3) and its phenomena that occur between two contacting bodies just before the start of
relative motion under gradually increasing external force
Note 1 to entry: See Figure 2.
© ISO 2017 – All rights reserved 3

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SIST ISO 4378-2:2020
ISO 4378-2:2017(E
...

INTERNATIONAL ISO
STANDARD 4378-2
Third edition
2017-07
Plain bearings — Terms, definitions,
classification and symbols —
Part 2:
Friction and wear
Paliers lisses — Termes, définitions, classification et symboles —
Partie 2: Frottement et usure
Reference number
ISO 4378-2:2017(E)
©
ISO 2017

---------------------- Page: 1 ----------------------
ISO 4378-2:2017(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2017 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 4378-2:2017(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
© ISO 2017 – All rights reserved iii

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ISO 4378-2:2017(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see the following
URL: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 123, Plain bearings, Subcommittee SC 6,
Terms and common items.
This third edition cancels and replaces the second edition (ISO 4378-2:2009), which has been technically
revised. The following changes have been made:
— editorial revision of the document;
— addition of 6 new figures;
— revision of clause numbers.
A list of all the parts in the ISO 4378 series can be found on the ISO website.
iv © ISO 2017 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 4378-2:2017(E)

Introduction
As there is a large number of multiple designations in the domain of plain bearings, there is a
considerable risk of error in the interpretation of standards and technical literature. This uncertainty
leads to the continuous addition of supplementary designations, which only serves to increase the
misunderstanding.
This document is an attempt to establish a uniform basic system of designations of friction and wear.
© ISO 2017 – All rights reserved v

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 4378-2:2017(E)
Plain bearings — Terms, definitions, classification and
symbols —
Part 2:
Friction and wear
1 Scope
This document specifies the most commonly used terms relating to friction and wear of plain bearings
with their definitions and classification.
For some terms and word combinations, their short forms are given, which can be used where they are
unambiguous. Self-explanatory terms are given without definitions.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1 General terms
3.1.1
external friction
force and its phenomenon of resistance to the relative motion between two bodies, originating at the
contact area of their surfaces and directed tangentially to them
3.1.2
internal friction
force and its phenomenon of resistance to the relative motion of particles or mass of a body with respect
to other particles or mass in the same body
© ISO 2017 – All rights reserved 1

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ISO 4378-2:2017(E)

3.1.3
friction
force and its phenomenon of resistance to the relative motion working tangentially with respect to the
common boundary between two bodies when, under the action of an external force, one body moves or
is at rest relative to the surface of the other
Note 1 to entry: See Figure 1.
Key
W weight of material
P normal force
F friction force
Figure 1 — Friction
3.1.4
friction force
force due to friction (3.1.3)
Note 1 to entry: See Figure 1.
3.1.5
coefficient of friction
ratio of the friction force (3.1.4) between two bodies to the normal force pressing these bodies together
3.1.6
friction angle
angle, the tangent of which is equal to the ratio of the friction force (3.1.4) to the normal force, or
coefficient of friction (3.1.5)
Note 1 to entry: See Figure 1.
3.1.7
wear
process of wear or the result of a wear process (3.1.8)
3.1.8
wear process
process of a loss of substance from a solid body surface in frictional conditions, which appears as a
gradual decrease of body dimensions and/or change of shape
Note 1 to entry: Rarely, in a broader sense, is there a process of permanent increase of body dimensions on the
surface without loss of substance.
2 © ISO 2017 – All rights reserved

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ISO 4378-2:2017(E)

3.1.9
wear rate
amount of wear (3.1.7) per unit sliding distance or per interval of time
Note 1 to entry: A distinction is made between “momentary” (at a definite moment) and “mean” wear rate (during
a definite interval of time).
3.1.10
specific wear rate
wear intensity
value of amount of wear (3.1.7) divided by the product of sliding distance (or time) and load; that is, the
ratio of wear rate (3.1.9) to the load
Note 1 to entry: Wear can be expressed in the units of length, volume, mass, etc.
Note 2 to entry: Wear intensity is distinguished as “momentary” or as “mean” wear intensity.
3.2 Types and characteristics of external friction and classification
3.2.1 Classification according to the presence of relative motion
3.2.1.1
static friction
friction (3.1.3) and its phenomena that occur between two contacting bodies before the start of relative
motion under increasing external force
Note 1 to entry: Friction that occurs at an extremely low sliding speed is also referred to as static friction.
Note 2 to entry: See Figure 2.
Key
f friction
L sliding distance
Figure 2 — Friction according to relative motion
3.2.1.2
maximum static friction
friction (3.1.3) and its phenomena that occur between two contacting bodies just before the start of
relative motion under gradually increasing external force
Note 1 to entry: See Figure 2.
© ISO 2017 – All rights reserved 3

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ISO 4378-2:2017(E)

3.2.1.3
dynamic friction
friction (3.1.3) and its phenomena between two bodies in relative motion
Note 1 to entry: See Figure 2.
3.2.2 Classification according to the mode of relative motion
3.2.2.1
sliding motion
relative motion between two bodies in contact when the contact areas of both bodies move with
different magnitudes and/or directions of tangential velocity
3.2.2.2
sliding friction
force and its phenomena of resistance to the sliding motion (3.2.2.1) between two bodies
Note 1 to entry: See Figure 1.
3.2.2.3
sliding velocity
difference
...

NORME ISO
INTERNATIONALE 4378-2
Troisième édition
2017-07
Paliers lisses — Termes, définitions,
classification et symboles —
Partie 2:
Frottement et usure
Plain bearings — Terms, definitions, classification and symbols —
Part 2: Friction and wear
Numéro de référence
ISO 4378-2:2017(F)
©
ISO 2017

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ISO 4378-2:2017(F)

DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2017, Publié en Suisse
Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni utilisée
sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie, l’affichage sur
l’internet ou sur un Intranet, sans autorisation écrite préalable. Les demandes d’autorisation peuvent être adressées à l’ISO à
l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2017 – Tous droits réservés

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ISO 4378-2:2017(F)

Sommaire Page
Avant-propos .iv
Introduction .v
1 Domaine d’application . 1
2 Références normatives . 1
3 Termes et définitions . 1
3.1 Termes généraux . 1
3.2 Types et caractéristiques de frottement interne et de classification . 3
3.2.1 Classification en fonction de l’existence d’un mouvement relatif . 3
3.2.2 Classification en fonction du mode de mouvement relatif . 4
3.2.3 Classification en fonction de la présence de lubrification . 5
3.3 Éléments constitutifs des ensembles avec palier lisses . 5
3.3.1 Usure mécanique . 5
3.3.2 Usure mécano-chimique . 7
3.3.3 Autres usures . 8
3.4 Phénomènes et procédés lors du frottement et de l’usure . 8
3.5 Vibrations et termes associés aux vibrations se produisant sur un arbre tournant
supporté par des paliers lisses . 9
© ISO 2017 – Tous droits réservés iii

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ISO 4378-2:2017(F)

Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération mondiale d’organismes
nationaux de normalisation (comités membres de l’ISO). L’élaboration des Normes internationales est
en général confiée aux comités techniques de l’ISO. Chaque comité membre intéressé par une étude
a le droit de faire partie du comité technique créé à cet effet. Les organisations internationales,
gouvernementales et non gouvernementales, en liaison avec l’ISO participent également aux travaux.
L’ISO collabore étroitement avec la Commission électrotechnique internationale (IEC) en ce qui
concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier de prendre note des différents
critères d’approbation requis pour les différents types de documents ISO. Le présent document a été
rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2 (voir www
.iso .org/ directives).
L’attention est appelée sur le fait que certains des éléments du présent document peuvent faire l’objet de
droits de propriété intellectuelle ou de droits analogues. L’ISO ne saurait être tenue pour responsable
de ne pas avoir identifié de tels droits de propriété et averti de leur existence. Les détails concernant
les références aux droits de propriété intellectuelle ou autres droits analogues identifiés lors de
l’élaboration du document sont indiqués dans l’Introduction et/ou dans la liste des déclarations de
brevets reçues par l’ISO (voir www .iso .org/ brevets).
Les appellations commerciales éventuellement mentionnées dans le présent document sont données
pour information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un
engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l’ISO liés à l’évaluation de la conformité, ou pour toute information au sujet de l’adhésion
de l’ISO aux principes de l’Organisation mondiale du commerce (OMC) concernant les obstacles
techniques au commerce (OTC), voir le lien suivant: w w w . i s o .org/ iso/ fr/ avant -propos .html
Le comité chargé de l’élaboration du présent document est l’ISO/TC 123, Paliers lisses, sous-comité SC 6,
Termes et sujets communs.
Cette troisième édition annule et remplace la seconde édition (ISO 4378-2:2009), qui a fait l’objet d’une
révision technique. Les modifications suivantes ont été apportées:
— révision mineure du document;
— ajout de 6 nouvelles figures;
— révision de la numérotation des articles.
Une liste de toutes les parties de la série ISO 4378 peut être trouvée sur le site web ISO.
iv © ISO 2017 – Tous droits réservés

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ISO 4378-2:2017(F)

Introduction
Un grand nombre de désignations multiples sont présentés dans le domaine des paliers lisses, ce
qui entraîne un risque considérable d’erreurs lors de l’interprétation des normes et de la littérature
technique. Du fait de cette incertitude, des désignations nouvelles sont constamment ajoutées, ce qui
augmente encore la confusion.
Le présent document est une tentative d’élaboration d’un système de base uniquement de désignation
concernant le frottement et l’usure.
© ISO 2017 – Tous droits réservés v

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NORME INTERNATIONALE ISO 4378-2:2017(F)
Paliers lisses — Termes, définitions, classification et
symboles —
Partie 2:
Frottement et usure
1 Domaine d’application
Le présent document spécifie les termes les plus couramment utilisés en matière frottement et d’usure
de paliers lisses, ainsi que leur définition et leur classification.
Les formes abrégées données pour certains termes peuvent être employées dans les cas où elles ne
créent aucune ambiguïté possible quant à leur interprétation. Les termes suffisamment explicites par
eux-mêmes ne sont pas définis.
2 Références normatives
Le présent document ne contient aucune référence normative.
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions suivants s’appliquent.
L’ISO et l’IEC tiennent à jour des bases de données terminologiques destinées à être utilisées en
normalisation, consultables aux adresses suivantes:
— IEC Electropedia: disponible à l’adresse http:// www .electropedia .org/
— ISO Online browsing platform: disponible à l’adresse http:// www .iso .org/ obp
3.1 Termes généraux
3.1.1
frottement externe
force et son phénomène de résistance au mouvement relatif de deux corps, prenant son origine au
niveau de l’aire de contact entre leurs surfaces et se dirigeant tangentiellement à celles-ci
3.1.2
frottement interne
force et son phénomène de résistance au mouvement relatif de particules ou de la masse par rapport à
d’autres particules ou de la masse au sein du même corps
3.1.3
frottement
force et son phénomène de résistance au mouvement relatif agissant tangentiellement par rapport à
la limite commune entre deux corps lorsque, sous l’action d’une force externe, un corps se déplace ou
reste immobile par rapport à la surface de l’autre corps
Note 1 à l’article: Voir Figure 1.
© ISO 2017 – Tous droits réservés 1

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ISO 4378-2:2017(F)

Légende
W poids du matériau
P force normale
F force de frottement
Figure 1 — Frottement
3.1.4
force de frottement
force due au frottement (3.1.3)
Note 1 à l’article: Voir Figure 1.
3.1.5
coefficient de frottement
rapport de la force de frottement (3.1.4) s’exerçant entre deux corps à la force normale maintenant ces
deux corps en contact
3.1.6
angle de frottement
angle dont la tangente est égale au rapport de la force de frottement (3.1.4) à la force normale, ou au
coefficient de frottement (3.1.5)
Note 1 à l’article: Voir Figure 1.
3.1.7
usure
processus d’usure ou résultat d’un processus d’usure (3.1.8)
3.1.8
processus d’usure
processus de perte de substance à la surface d’un corps solide en condition de frottement qui apparaît
comme une diminution graduelle des dimensions du corps et/ou d’une modification de la forme
Note 1 à l’article: En de rares cas, dans un sens plus large, le processus d’usure est associé à une augmentation
permanente des dimensions d’un corps à sa surface, sans perte de substance.
3.1.9
taux d’usure
quantité d’usure (3.1.7) par unité de distance ou de temps de glissement
Note 1 à l’article: On fait une distinction entre taux d’usure «instantané» (à un moment donné) et taux d’usure
«moyen» (durant un intervalle de temps donné).
2 © ISO 2017 – Tous droits réservés

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ISO 4378-2:2017(F)

3.1.10
taux d’usure spécifique
intensité d’usure
degré d’usure
valeur de la quantité d’usure (3.1.7) divisée par le produit de la distance (ou du temps) de glissement et
de la charge, c’est-à-dire le rapport du taux d’usure (3.1.9) à la charge
Note 1 à l’article: L’usure peut être exprimée en unités de longueur, de volume, de masse, etc.
Note 2 à l’article: On fait la distinction entre intensité (degré) d’usure «instantané(e)» et intensité (degré) d’usure
«moyen(ne)».
3.2 Types et caractéristiques de frottement interne et de classification
3.2.1 Classification en fonction de l’existence d’un mouvement relatif
3.2.1.1
frottement statique
frottement (3.1.3) et ses phénomènes associés qui se produisent entre deux corps en contact avant le
début d’un mouvement relatif sous une force externe augmentant graduellement
Note 1 à l’article: Un frottement qui se produit à une vitesse de glissement extrêmement faible est également
désigné par frottement statique.
Note 2 à l’article: Voir Figure 2.
Légende
f frottement
L distance de glissement
Figure 2 — Frottement selon le movement relatif
3.2.1.2
frottement statique maximal
frottement (3.1.3) et ses phénomènes associés qui se produisent entre deux corps en contact juste avant
le début d’un mouvement sous une force externe augmentant graduelle
...