ISO 2203:1973
(Main)Technical drawings - Conventional representation of gears
Technical drawings - Conventional representation of gears
Establishes how to draw the toothed portion of gears including worm gearing and chain wheels. Applicable to detail drawings (individual gears) and assembly drawings (gear pairs). As a fundamental principle a gear is represented (except in axial section) as a solid part without teeth, but with the addition of the pitch surface in a thin long dash-and-dot line. For uniformity all figures are in first angle projection.
Dessins techniques — Représentation conventionnelle des engrenages
La présente Norme Internationale établit une représentation conventionnelle des dentures des engrenages, ainsi que des vis sans fin et des roues à chaîne. Elle s'applique aux dessins de détail et dessins d'ensemble. Selon les principes de base, une roue d'engrenage est représentée (sauf en coupe axiale) comme une pièce pleine non dentée, avec pour seule adjonction, le tracé de la surface primitive, en trait mixte fin. NOTE -- Pour des raisons d'uniformité, dans la présente Norme internationale, les figures sont en projection du premier dièdre (Méthode E). Il est entendu que les principes établis s'appliquent également à la projection du troisième dièdre (Méthode A).
Tehnične risbe - Običajno prikazovanje zobnikov
General Information
- Status
- Published
- Publication Date
- 28-Feb-1973
- Technical Committee
- ISO/TC 10/SC 6 - Mechanical engineering documentation
- Drafting Committee
- ISO/TC 10/SC 6 - Mechanical engineering documentation
- Current Stage
- 9093 - International Standard confirmed
- Start Date
- 10-Jun-2024
- Completion Date
- 13-Dec-2025
Overview
ISO 2203:1973 specifies conventional representation practices for the toothed portions of gears used on technical drawings. The standard applies to individual (detail) drawings and assembly drawings such as gear pairs, worm gearing and chain wheels. Its purpose is to ensure uniform, clear depiction of gears across engineering documentation using a consistent projection method and simplified tooth representation.
Key principles include:
- A gear is normally shown as a solid part without explicitly drawn teeth (except in axial sections).
- The pitch surface is indicated by a thin long chain line (pitch circle or median pitch circle for worm wheels) even in concealed or sectional views.
- All illustrative figures in the standard use first-angle projection for uniformity (the principles can be applied equally in third-angle projection).
Key Topics
Contours and edges: Represent gear contours and edges as if bounded by the tip surface in unsectioned views. In axial sections, show a spur-gear appearance with two diametrically opposed teeth unsectioned, even for non-spur gears or odd tooth counts.
Pitch surface: Draw the pitch surface with a thin long chain line. In projections normal to the axis, use the pitch circle (external for bevel gears; median for worm wheels). In projections parallel to the axis, represent the apparent contour and extend the line beyond the gear contour on each side.
Root surface and teeth: Generally omit root-surface lines on unsectioned views; show them in sectional views or when helpful. If one or two teeth must be shown (to define ends of a toothed portion or position relative to an axial plane), represent them as thick continuous lines. Indicate tooth direction (helical, double-helical, spiral) on the tooth-surface view using three thin continuous lines of the corresponding form.
Assembly representation: Apply the same detail-drawing rules to assembly views. For bevel gear pairs shown parallel to the axis, extend the pitch-surface line to where the axes meet. In mesh, gears are not assumed to hide one another except when one physically conceals part of the other or when both are in axial section.
Applications
This standard is essential for:
- Engineering drawings of gear components and assemblies
- Manufacturing drawings where consistent gear depiction aids interpretation
- Design documentation for transmissions, worm drives and chain systems
- Technical publications and drawing templates used by engineering teams
Benefits include improved clarity, reduced ambiguity in interpretation, and consistent representation across suppliers and engineering teams.
Related Standards
While ISO 2203:1973 focuses on graphical representation, it complements other standards that define gear geometry, tooth profiles and tolerancing. When preparing drawings, reference ISO 2203 for depiction conventions alongside applicable standards for gear dimensions, materials and inspection criteria.
For practical use, follow the ISO 2203 rules for pitch-surface lines, projection choice and selective tooth depiction to produce clear, standardized technical drawings of gears and related components.
ISO 2203:1973 - Technical drawings — Conventional representation of gears Released:1. 03. 1973
ISO 2203:1973 - Dessins techniques — Représentation conventionnelle des engrenages Released:1. 03. 1973
Frequently Asked Questions
ISO 2203:1973 is a standard published by the International Organization for Standardization (ISO). Its full title is "Technical drawings - Conventional representation of gears". This standard covers: Establishes how to draw the toothed portion of gears including worm gearing and chain wheels. Applicable to detail drawings (individual gears) and assembly drawings (gear pairs). As a fundamental principle a gear is represented (except in axial section) as a solid part without teeth, but with the addition of the pitch surface in a thin long dash-and-dot line. For uniformity all figures are in first angle projection.
Establishes how to draw the toothed portion of gears including worm gearing and chain wheels. Applicable to detail drawings (individual gears) and assembly drawings (gear pairs). As a fundamental principle a gear is represented (except in axial section) as a solid part without teeth, but with the addition of the pitch surface in a thin long dash-and-dot line. For uniformity all figures are in first angle projection.
ISO 2203:1973 is classified under the following ICS (International Classification for Standards) categories: 01.100.20 - Mechanical engineering drawings; 21.200 - Gears. The ICS classification helps identify the subject area and facilitates finding related standards.
You can purchase ISO 2203:1973 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of ISO standards.
Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-1995
7HKQLþQHULVEH2ELþDMQRSULND]RYDQMH]REQLNRY
Technical drawings -- Conventional representation of gears
Dessins techniques -- Représentation conventionnelle des engrenages
Ta slovenski standard je istoveten z: ISO 2203:1973
ICS:
01.100.20 Konstrukcijske risbe Mechanical engineering
drawings
21.200 Gonila Gears
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
INTERNATIONAL STANDARD
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION l EXfiYHAPO,llHAB OPrAHH3ALU+iR n0 CfAHAAFIX3AU[HH .ORGANISATION INTERNATIONALE DE NORMALISATION
Conventional representation of gears
Technical drawings -
First edition - 1973-03-15
UDC 744.4 : 621.83 Ref. No. IS0 2203-1973 (E)
Descriptors : drawings, engineering drawings, gears, chain wheels, representation.
Price based on 6 pages
FOREWORD
Is0 (the International Organization for Standardization) is a worldwide federation
of national standards institutes (IS0 Member Bodies). The work of developing
International Standards is carried out through IS0 Technical Committees. Every
Member Body interested in a subject for which a Technical Committee has been set
up has the right to be represented on that Committee. International organizations,
governmental and nongovernmental, in liaison with ISO, also take part in the work.
Draft International Standards adopted by the Technical Committees are circulated
to the Member Bodies for approval before their acceptance as International
Standards by the IS0 Council.
International Standard IS0 2203 was drawn up by Technical Committee
lSO/TC IO, Technical drawings, and circulated to the Member Bodies in
January 1971.
It has been approved by the Member Bodies of the following countries :
Hungary Portugal
Australia
Austria India Romania
Belgium Ireland South Africa, Rep. of
Canada Israel Sweden
Chile Italy Switzerland
Czechoslovakia Turkey
Japan
Korea, Dem.P.Rep. of United Kingdom
Denmark
Korea, Rep. of U.S.A.
Egypt, Arab Rep. of
Netherlands U.S.S.R.
France
New Zealand
Germany
Greece Norway
No Member Body expressed disapproval of the document.
0 International Organization for Standardization, 1973 l
Printed in Switzerland.
INTERNATIONAL STANDARD IS022034973 (E)
Conventional representation of gears
Technical drawings -
1 SCOPE AND FIELD OF APPLICATION
This International Standard establishes the conventional
representation- of the toothed portion of gears including
worm gearing and chain wheels. It is applicable to detail
drawings and assembly drawings.
As a fundamental principle a gear is represented (except in
axial section) as a solid part without teeth, but with the
addition of the pitch surface in a thin long chain line.
NOTE - For uniformity all figures in this international Standard
are in first angle projection (Method EL It should be understood
that the third angle projection (Method A) could equally well have
FIGURE 1
been used without prejudice to the principles established.
2 DETAIL DRAWINGS (INDIVIDUAL GEARS)
2.1 Contours and edges
Represent the contours and the edges of each gear (see
Figures 1,2 and 3), as if they were,
- in an unsectioned view, a solid gear bounded by the
tip surface;
-
in an axial section, a spur gear having two
diametrically opposed teeth, represented unsectioned,
FIGURE 2
even in the case of a gear that does not have spur teeth
or that has an odd number of teeth.
2.2 Pitch surface
D
...
INTERNATIONAL STANDARD
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION l EXfiYHAPO,llHAB OPrAHH3ALU+iR n0 CfAHAAFIX3AU[HH .ORGANISATION INTERNATIONALE DE NORMALISATION
Conventional representation of gears
Technical drawings -
First edition - 1973-03-15
UDC 744.4 : 621.83 Ref. No. IS0 2203-1973 (E)
Descriptors : drawings, engineering drawings, gears, chain wheels, representation.
Price based on 6 pages
FOREWORD
Is0 (the International Organization for Standardization) is a worldwide federation
of national standards institutes (IS0 Member Bodies). The work of developing
International Standards is carried out through IS0 Technical Committees. Every
Member Body interested in a subject for which a Technical Committee has been set
up has the right to be represented on that Committee. International organizations,
governmental and nongovernmental, in liaison with ISO, also take part in the work.
Draft International Standards adopted by the Technical Committees are circulated
to the Member Bodies for approval before their acceptance as International
Standards by the IS0 Council.
International Standard IS0 2203 was drawn up by Technical Committee
lSO/TC IO, Technical drawings, and circulated to the Member Bodies in
January 1971.
It has been approved by the Member Bodies of the following countries :
Hungary Portugal
Australia
Austria India Romania
Belgium Ireland South Africa, Rep. of
Canada Israel Sweden
Chile Italy Switzerland
Czechoslovakia Turkey
Japan
Korea, Dem.P.Rep. of United Kingdom
Denmark
Korea, Rep. of U.S.A.
Egypt, Arab Rep. of
Netherlands U.S.S.R.
France
New Zealand
Germany
Greece Norway
No Member Body expressed disapproval of the document.
0 International Organization for Standardization, 1973 l
Printed in Switzerland.
INTERNATIONAL STANDARD IS022034973 (E)
Conventional representation of gears
Technical drawings -
1 SCOPE AND FIELD OF APPLICATION
This International Standard establishes the conventional
representation- of the toothed portion of gears including
worm gearing and chain wheels. It is applicable to detail
drawings and assembly drawings.
As a fundamental principle a gear is represented (except in
axial section) as a solid part without teeth, but with the
addition of the pitch surface in a thin long chain line.
NOTE - For uniformity all figures in this international Standard
are in first angle projection (Method EL It should be understood
that the third angle projection (Method A) could equally well have
FIGURE 1
been used without prejudice to the principles established.
2 DETAIL DRAWINGS (INDIVIDUAL GEARS)
2.1 Contours and edges
Represent the contours and the edges of each gear (see
Figures 1,2 and 3), as if they were,
- in an unsectioned view, a solid gear bounded by the
tip surface;
-
in an axial section, a spur gear having two
diametrically opposed teeth, represented unsectioned,
FIGURE 2
even in the case of a gear that does not have spur teeth
or that has an odd number of teeth.
2.2 Pitch surface
Draw the pitch surface with a thin, long chain line, even in
concealed portions and sectional views, and represent it,
- in a projection normal to the axis, by its pitch circle
(external pitch circle in the case of a bevel gear and the
median pitch circle in the case of a worm wheel) (see
F
...
NORME INTERNATIONALE
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION l EX~YHAPO~HAR OPI-AHW3Al@ïII l-I0 CTAHAAPTH3AUHH .ORGANISATION INTERNATIONALE DE NORMALISATION
Dessins techniques - Représentation conventionnelle des
engrenages
Première édition - 1973 -03-15
CDU 744.4 : 621.83
Réf. No : ISO 2203-1973 (F)
Descripteurs : dessin, dessin industriel, engrenage, roue pour chaîne, représentation.
Prix basé sur 6 pages
AVANT-PROPOS
ISO (Organisation Internationale de Normalisation) est une fédération mondiale
d’organismes nationaux de normalisation (Comités Membres KO). L’élaboration de
Normes Internationales est confiée aux Comités Techniques ISO. Chaque Comité
Membre intéressé par une étude a le droit de faire partie du Comité Technique
correspondant. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec I’ISO, participent également aux travaux.
Les Projets de Normes Internationales adoptés par les Comités Techniques sont
soumis aux Comités Membres pour approbation, avant leur acceptation comme
Normes Internationales par le Conseil de I’ISO.
La Norme Internationale ISO 2203 a été établie par le Comité Technique
lSO/TC 10, Dessins technigues, et soumise aux Comités Membres en janvier 1971.
Elle a été approuvée par les Comités Membres des pays suivants :
Afrique du Sud, Rép. d’ France Portugal
Allemagne Grèce Roumanie
Hongrie
Australie Royaume-Uni
Autriche Inde Suède
Belgique Irlande Suisse
Canada Israël Tchécoslovaquie
Chili Italie Turquie
Corée, Rép.dém.p.de
Japon U.R.S.S.
Norvège
Corée, Rép. de U.S.A.
Nouvelle-Zélande
Danemark
Egypte, Rép. arabe d’ Pays-Bas
Aucun Comité Membre n’a désapprouvé le document.
0 Organisation Internationale de Normalisation, 1973 l
Imprime en Suisse.
ISO 2203-1973 (F)
NORME INTERNATIONALE
Dessins techniques - Représentation conventionnelle des
engrenages
1 OBJET ET DOWlAINE D’APPLICATION
L
présente Norme Internationale établit une
La
représentation conventionnelle des dentures des engrenages,
ainsi que des vis sans fin et des roues à chaîne. Elle
s’applique aux dessins de détail et dessins d’ensemble. Ii
-
/
T \
Selon les principes de base, une roue d’engrenage est ,
\
représentée (sauf en coupe axiale) comme une pièce pleine
/
non dentée, avec pour seule adjonction, le tracé de la
I \
,
,
surface primitive, en trait mixte fin.
++# s
a
NOTE - Pour des raisons d’uniformité, dans la présente Norme FIGURE 1
Internationale, les figures sont en projection du premier dièdre
est entendu que les principes 6tablis s’appliquent
(Méthode E). II
également à la projection du troisième dièdre (Méthode A).
2 DESSINS DE DÉTAIL (ROUES ISOLÉES)
2.1 Contours et arêtes
Représenter les contours et les arêtes de chaque roue (voir
Figures 1, 2 et 3) comme s’il s’agissait,
-
en vue non coupée, d’une roue non dentée limitée
par la surface de tête;
-
en coupe axiale, d’une roue à denture droite ayant FIGURE 2
deux dents diamétralement opposées, représentées non
coupées (même dans le cas d’une denture non droite, ou
d’un nombre impair de dents).
2.2 Surface primitive de fonctionnement
Tracer la surface primitive en trait mixte fin, même dans les
parties cachées et dans les vues en coupe, et la représenter,
-
en projection normale à
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