SIST ISO 4378-4:2015

Plain bearings - Terms, definitions, classification and symbols - Part 4: Basic symbols

ISO 4378-4:2009 defines basic symbols for use in the field of plain bearings. Additional signs are also defined for use as superscripts and subscripts.
The characters employed are drawn from the Latin and Greek alphabets, Arabic numerals and other signs, for example points, commas, horizontal lines or asterisks. In the simplest case, an application symbol consists of the basic character alone; in the most complex, of the basic character with subscripts and superscripts (additional signs). For the purposes of international applicability, all basic symbols and additional signs have been derived from English words, and designations used in technical literature up to now have been adopted as far as possible. Wide conformity of the symbols for all types of plain bearings has been attempted.
This classification is established for use in calculations and technological and geometrical determinations, as well as in the quality assurance of plain bearings.

Gleitlager - Begriffe, Definitionen und Einteilung - Teil 4: Berechnungsgrößen und deren Symbole

Paliers lisses - Termes, définitions, classification et symboles - Partie 4: Symboles de base

L'ISO 4378-4:2009 d�finit les symboles de base � utiliser dans le domaine des paliers lisses. Des signes compl�mentaires sont �galement d�finis pour �tre utilis�s comme indices ou exposants.
Les caract�res utilis�s sont extraits des alphabets latin et grec, des chiffres arabes et d'autres signes tels que des points, des virgules, des traits horizontaux ou des ast�risques. Dans le cas le plus simple, un symbole d'application consiste uniquement en un caract�re de base; et dans le cas le plus complexe, en un caract�re de base avec des indices et des exposants (signes compl�mentaires). � des fins d'application internationale, tous les symboles de base et signes compl�mentaires ont �t� d�riv�s de mots anglais et, jusqu'� maintenant, toutes les d�signations utilis�es dans la litt�rature technique ont �t�, autant que possible, adopt�es. Il a aussi �t� tent� de parvenir � une large conformit� des symboles pour tous les types de paliers lisses.
La pr�sente classification a �t� �labor�e pour �tre utilis�e dans les calculs et d�terminations technologiques et g�om�triques, ainsi que pour l'assurance qualit� des paliers lisses.

Drsni ležaji - Izrazi, definicije, klasifikacija in simboli - 4. del: Osnovni simboli

Ta del standarda ISO 4378 določa osnovne simbole, ki se uporabljajo na področju drsnih ležajev. Dodatni simboli so lahko tudi nadpisani in podpisani. Uporabljeni so znaki iz latinske in grške abecede, arabske številke in drugi znaki, na primer pike, vejice, vodoravne črte ali zvezdice. V najpreprostejših primerih je uporabljen simbol sestavljen samo iz osnovnega znaka, v bolj zapletenih primerih pa je uporabljen osnovni znak z nadpisom in podpisom (dodatni znaki).
Za zagotovitev mednarodne uporabnosti vsi osnovni simboli in dodatni znaki izvirajo iz angleških besed, pri čemer se čim bolj upoštevajo oznake, ki se uporabljajo v strokovni literaturi. Poskušala se je zagotoviti splošna skladnost simbolov za vse vrste drsnih ležajev. Ta razvrstitev je določena za uporabo pri izračunih ter tehnološkem in geometričnem določanju
ter zagotavljanju kakovosti drsnih ležajev.  Količine z določeno vrednostjo za določeno konstrukcijo so označene z velikimi tiskanimi črkami, če je to mogoče. Glede na posebno področje uporabe se osnovni opredeljeni znaki uporabljajo samostojno ali se po potrebi ustrezno kombinirajo z dodatnimi znaki, da se čim bolj zmanjša nevarnost zamenjave; večkratnim poimenovanjem se je mogoče izogniti z ustreznim indeksiranjem z dodatnimi znaki.

General Information

• Status: Published
• Public Enquiry End Date: 31-Jul-2008
• Publication Date: 16-Feb-2015
• 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: 29-Jan-2015
• Due Date: 05-Apr-2015
• Completion Date: 17-Feb-2015
• Ref Project: ISO 4378-4:2009 - Plain bearings — Terms, definitions, classification and symbols — Part 4: Basic symbols

Relations

• Replaces: SIST ISO 4378-4:2002 - Plain bearings -- Terms, definitions and classification -- Part 4: Calculation parameters and their symbol
• Effective Date: 01-Mar-2015
• Replaces: SIST ISO 7904-1:2002 - Plain bearings -- Symbols -- Part 1: Basic symbols
• Effective Date: 01-Mar-2015

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 4378-4
Second edition
2009-09-01

Plain bearings — Terms, definitions,
classification and symbols —
Part 4:
Basic symbols
Paliers lisses — Termes, définitions, classification et symboles —
Partie 4: Symboles de base




Reference number
ISO 4378-4:2009(E)
©
ISO 2009

---------------------- Page: 1 ----------------------
ISO 4378-4:2009(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


COPYRIGHT PROTECTED DOCUMENT


©  ISO 2009
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland

ii © ISO 2009 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 4378-4:2009(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Basic characters.1
4 Additional signs.2
4.1 Subscripts .2
4.2 Superscripts.2
5 Application and distinction by means of basic characters, subscripts and superscripts .2
6 Symbols and terms .2
6.1 General .2
6.2 Basic characters of the Roman alphabet.2
6.3 Basic characters of the Greek alphabet.5
7 Additional signs.6
7.1 Subscripts .6
7.2 Superscripts.11

© ISO 2009 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 4378-4:2009(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 4378-4 was prepared by Technical Committee ISO/TC 123, Plain bearings, Subcommittee SC 6, Terms
and common items.
This second edition cancels and replaces the first edition (ISO 4378-4:1997) and ISO 7904-1:1995, which
have been technically revised.
ISO 4378 consists of the following parts, under the general title Plain bearings — Terms, definitions,
classification and symbols:
⎯ Part 1: Design, bearing materials and their properties
⎯ Part 2: Friction and wear
⎯ Part 3: Lubrication
⎯ Part 4: Basic symbols
⎯ Part 5: Application of symbols
iv © ISO 2009 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 4378-4:2009(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 part of ISO 4378 is an attempt to elaborate a uniform basic system of symbols.

© ISO 2009 – All rights reserved v

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 4378-4:2009(E)

Plain bearings — Terms, definitions, classification and
symbols —
Part 4:
Basic symbols
1 Scope
This part of ISO 4378 defines basic symbols for use in the field of plain bearings. Additional signs are also
defined for use as superscripts and subscripts.
The characters employed are drawn from the Latin and Greek alphabets, Arabic numerals and other signs, for
example points, commas, horizontal lines or asterisks. In the simplest case, an application symbol consists of
the basic character alone; in the most complex, of the basic character with subscripts and superscripts
(additional signs).
For the purposes of international applicability, all basic symbols and additional signs have been derived from
English words, and designations used in technical literature up to now have been adopted as far as possible.
Wide conformity of the symbols for all types of plain bearings has been attempted.
This classification is established for use in calculations and technological and geometrical determinations, as
well as in the quality assurance of plain bearings.
Quantities having a fixed value for a certain construction are designated by capital letters, where possible.
Depending on the special field of application, the basic characters specified are for stand-alone use or
appropriately combined with additional signs, where necessary, to minimize the risk of confusion; multiple
designations can be avoided by suitable indexing with additional signs.
2 Normative references
The following referenced documents are indispensable for the application 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 4378-5, Plain bearings — Terms, definitions, classification and symbols — Part 5: Application of symbols
3 Basic characters
Basic characters consist of one or, in exceptional cases, two capital or Iower-case Ietters.
Variables shall be in italic typeface, abbreviations shall be in Roman typeface.
EXAMPLE N = rotational speed, VG = Viscosity Grade.
© ISO 2009 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO 4378-4:2009(E)
4 Additional signs
4.1 Subscripts
Subscripts may consist of one, two or three letters, digits or letter/digit combinations. In general, the first letter
of a subscript corresponds to the first Ietter of the English concept, which is referred to by the subscript.
Subsequent letters shall also follow this concept. The expressions used should be as short as possible.
When the signs correspond to a variable, they shall be in italic typeface; when they refer to an abbreviation,
they shall be in Roman typeface.
EXAMPLE c = circular, cr = critical, cal = calculated.
If subscripts are combined, they shall be separat
...

SLOVENSKI STANDARD
SIST ISO 4378-4:2015
01-marec-2015
1DGRPHãþD
SIST ISO 4378-4:2002
SIST ISO 7904-1:2002
Drsni ležaji - Izrazi, definicije, klasifikacija in simboli - 4. del: Osnovni simboli
Plain bearings - Terms, definitions, classification and symbols - Part 4: Basic symbols
Gleitlager - Begriffe, Definitionen und Einteilung - Teil 4: Berechnungsgrößen und deren
Symbole
Paliers lisses - Termes, définitions, classification et symboles - Partie 4: Symboles de
base
Ta slovenski standard je istoveten z: ISO 4378-4:2009
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 4378-4:2015 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST ISO 4378-4:2015

---------------------- Page: 2 ----------------------

SIST ISO 4378-4:2015

INTERNATIONAL ISO
STANDARD 4378-4
Second edition
2009-09-01

Plain bearings — Terms, definitions,
classification and symbols —
Part 4:
Basic symbols
Paliers lisses — Termes, définitions, classification et symboles —
Partie 4: Symboles de base




Reference number
ISO 4378-4:2009(E)
©
ISO 2009

---------------------- Page: 3 ----------------------

SIST ISO 4378-4:2015
ISO 4378-4:2009(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


COPYRIGHT PROTECTED DOCUMENT


©  ISO 2009
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland

ii © ISO 2009 – All rights reserved

---------------------- Page: 4 ----------------------

SIST ISO 4378-4:2015
ISO 4378-4:2009(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Basic characters.1
4 Additional signs.2
4.1 Subscripts .2
4.2 Superscripts.2
5 Application and distinction by means of basic characters, subscripts and superscripts .2
6 Symbols and terms .2
6.1 General .2
6.2 Basic characters of the Roman alphabet.2
6.3 Basic characters of the Greek alphabet.5
7 Additional signs.6
7.1 Subscripts .6
7.2 Superscripts.11

© ISO 2009 – All rights reserved iii

---------------------- Page: 5 ----------------------

SIST ISO 4378-4:2015
ISO 4378-4:2009(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 4378-4 was prepared by Technical Committee ISO/TC 123, Plain bearings, Subcommittee SC 6, Terms
and common items.
This second edition cancels and replaces the first edition (ISO 4378-4:1997) and ISO 7904-1:1995, which
have been technically revised.
ISO 4378 consists of the following parts, under the general title Plain bearings — Terms, definitions,
classification and symbols:
⎯ Part 1: Design, bearing materials and their properties
⎯ Part 2: Friction and wear
⎯ Part 3: Lubrication
⎯ Part 4: Basic symbols
⎯ Part 5: Application of symbols
iv © ISO 2009 – All rights reserved

---------------------- Page: 6 ----------------------

SIST ISO 4378-4:2015
ISO 4378-4:2009(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 part of ISO 4378 is an attempt to elaborate a uniform basic system of symbols.

© ISO 2009 – All rights reserved v

---------------------- Page: 7 ----------------------

SIST ISO 4378-4:2015

---------------------- Page: 8 ----------------------

SIST ISO 4378-4:2015
INTERNATIONAL STANDARD ISO 4378-4:2009(E)

Plain bearings — Terms, definitions, classification and
symbols —
Part 4:
Basic symbols
1 Scope
This part of ISO 4378 defines basic symbols for use in the field of plain bearings. Additional signs are also
defined for use as superscripts and subscripts.
The characters employed are drawn from the Latin and Greek alphabets, Arabic numerals and other signs, for
example points, commas, horizontal lines or asterisks. In the simplest case, an application symbol consists of
the basic character alone; in the most complex, of the basic character with subscripts and superscripts
(additional signs).
For the purposes of international applicability, all basic symbols and additional signs have been derived from
English words, and designations used in technical literature up to now have been adopted as far as possible.
Wide conformity of the symbols for all types of plain bearings has been attempted.
This classification is established for use in calculations and technological and geometrical determinations, as
well as in the quality assurance of plain bearings.
Quantities having a fixed value for a certain construction are designated by capital letters, where possible.
Depending on the special field of application, the basic characters specified are for stand-alone use or
appropriately combined with additional signs, where necessary, to minimize the risk of confusion; multiple
designations can be avoided by suitable indexing with additional signs.
2 Normative references
The following referenced documents are indispensable for the application 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 4378-5, Plain bearings — Terms, definitions, classification and symbols — Part 5: Application of symbols
3 Basic characters
Basic characters consist of one or, in exceptional cases, two capital or Iower-case Ietters.
Variables shall be in italic typeface, abbreviations shall be in Roman typeface.
EXAMPLE N = rotational speed, VG = Viscosity Grade.
© ISO 2009 – All rights reserved 1

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SIST ISO 4378-4:2015
ISO 4378-4:2009(E)
4 Additional signs
4.1 Subscripts
...

NORME ISO
INTERNATIONALE 4378-4
Deuxième édition
2009-09-01

Paliers lisses — Termes, définitions,
classification et symboles —
Partie 4:
Symboles de base
Plain bearings — Terms, definitions, classification and symbols —
Part 4: Basic symbols




Numéro de référence
ISO 4378-4:2009(F)
©
ISO 2009

---------------------- Page: 1 ----------------------
ISO 4378-4:2009(F)
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DOCUMENT PROTÉGÉ PAR COPYRIGHT


©  ISO 2009
Droits de reproduction réservés. Sauf prescription différente, 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 et les microfilms, sans l'accord écrit
de l'ISO à l'adresse ci-après ou du comité membre de l'ISO dans le pays du demandeur.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Publié en Suisse

ii © ISO 2009 – Tous droits réservés

---------------------- Page: 2 ----------------------
ISO 4378-4:2009(F)
Sommaire Page
Avant-propos .iv
Introduction.v
1 Domaine d'application .1
2 Références normatives.1
3 Caractères de base.1
4 Signes complémentaires .2
4.1 Indices .2
4.2 Exposants.2
5 Application et distinction au moyen de caractères de base, indices et exposants .2
6 Symboles et termes.2
6.1 Généralités .2
6.2 Caractères de base (alphabet romain) .2
6.3 Caractères de base (alphabet grec).5
7 Signes complémentaires .6
7.1 Indices .6
7.2 Exposants.11

© ISO 2009 – Tous droits réservés iii

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ISO 4378-4:2009(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 (CEI) en ce qui concerne la normalisation électrotechnique.
Les Normes internationales sont rédigées conformément aux règles données dans les Directives ISO/CEI,
Partie 2.
La tâche principale des comités techniques est d'élaborer les Normes internationales. Les projets de Normes
internationales adoptés par les comités techniques sont soumis aux comités membres pour vote. Leur
publication comme Normes internationales requiert l'approbation de 75 % au moins des comités membres
votants.
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.
L'ISO 4378-4 a été élaborée par le comité technique ISO/TC 123, Paliers lisses, sous-comité SC 6, Termes et
sujets communs.
Cette deuxième édition annule et remplace la première édition (ISO 4378-4:1997) ainsi que l'ISO 7904-1:1995,
qui ont fait l'objet d'une révision technique.
L'ISO 4378 comprend les parties suivantes, présentées sous le titre général Paliers lisses — Termes,
définitions, classification et symboles:
⎯ Partie 1: Conception, matériaux pour paliers et leurs propriétés
⎯ Partie 2: Frottement et usure
⎯ Partie 3: Lubrification
⎯ Partie 4: Symboles de base
⎯ Partie 5: Application des symboles
iv © ISO 2009 – Tous droits réservés

---------------------- Page: 4 ----------------------
ISO 4378-4:2009(F)
Introduction
Un grand nombre de désignations multiples sont présentes 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.
La présente partie de l'ISO 4378 est une tentative d'élaboration d'un système de base unique des symboles
utilisés dans le domaine des paliers lisses.

© ISO 2009 – Tous droits réservés v

---------------------- Page: 5 ----------------------
NORME INTERNATIONALE ISO 4378-4:2009(F)

Paliers lisses — Termes, définitions, classification et
symboles —
Partie 4:
Symboles de base
1 Domaine d'application
La présente partie de l'ISO 4378 définit les symboles de base à utiliser dans le domaine des paliers lisses.
Des signes complémentaires sont également définis pour être utilisés comme indices ou exposants.
Les caractères utilisés sont extraits des alphabets latin et grec, des chiffres arabes et d'autres signes tels que
des points, des virgules, des traits horizontaux ou des astérisques. Dans le cas le plus simple, un symbole
d'application consiste uniquement en un caractère de base, et, dans le cas le plus complexe, en un caractère
de base avec des indices et des exposants (signes complémentaires).
À des fins d'application internationale, tous les symboles de base et signes complémentaires ont été dérivés
de mots anglais et, jusqu'à maintenant, toutes les désignations utilisées dans la littérature technique ont été,
autant que possible, adoptées. Il a aussi été tenté de parvenir à une large conformité des symboles pour tous
les types de paliers lisses.
La présente classification a été élaborée pour être utilisée dans les calculs et déterminations technologiques
et géométriques, ainsi que pour l'assurance qualité des paliers lisses.
Les grandeurs possédant une valeur fixe pour un certain type de construction sont désignées, si possible, par
des lettres majuscules. Selon le domaine d'application particulier, les caractères de base sont spécifiés pour
une utilisation seuls ou bien judicieusement combinés avec des signes complémentaires, lorsque nécessaire,
pour réduire le risque de confusion; les désignations multiples peuvent être évitées par un indexage approprié
avec des signes complémentaires.
2 Références normatives
Les documents de référence suivants sont indispensables pour l'application du présent document. Pour les
références datées, seule l'édition citée s'applique. Pour les références non datées, la dernière édition du
document de référence s'applique (y compris les éventuels amendements).
ISO 4378-5, Paliers lisses — Termes, définitions, classification et symboles — Partie 5: Application des
symboles
3 Caractères de base
Les caractères de base consistent en une, exceptionnellement deux, lettres majuscules ou minuscules.
Les variables doivent figurer en italique, les abréviations en caractères romains.
EXEMPLE N = vitesse de rotation, VG = degré de viscosité.
© ISO 2009 – Tous droits réservés 1

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ISO 4378-4:2009(F)
4 Signes complémentaires
4.1 Indices
Les indices peuvent se composer d'une, deux ou trois lettres ou chiffres ou de combinaisons de lettre/chiffre.
En général, la première lettre d'un indice correspond à la première lettre de la notion anglaise qui fait l'objet de
l'indice. Les lettres suivantes doivent aussi être comprises dans la notion concernée. Il convient que les
expressions utilisées soient aussi courtes que possible.
Lorsque les signes correspondent à une variable, ils doivent figurer en italique, et, lorsqu'ils correspondent à
une abréviation, ils doivent figurer en caractères roma
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