SIST EN ISO 2203:1998

Technical drawings - Conventional representation of gears (ISO 2203:1973)

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.

Technische Zeichnungen - Darstellung von Zahnrädern (ISO 2203:1973)

Diese Norm legt die herkömmliche Darstellung der gezahnten Teile von Zahnrädern einschließlich Schnecken- und Kettenrädern fest. Sie gilt für Teilzeichnungen und Zusammenstellungszeichnungen. Ein Zahnrad wird grundsätzlich (ausgenommen in Schnittdarstellungen) als ein ganzes Teil ohne einzelne Zähne dargestellt, aber die Bezugsfläche wird als schmale Strichpunktlinie hinzugefügt.

Dessins techniques - Représentation conventionnelle des engrenages (ISO 2203:1973)

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: 30-Apr-1998
• ICS: 01.100.20 - Mechanical engineering drawings
• ICS: 21.200 - Gears
• Technical Committee: TRS - Technical drawings, quantities, units, symbols and graphical symbols
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-May-1998
• Due Date: 01-May-1998
• Completion Date: 01-May-1998
• Ref Project: EN ISO 2203:1997 - Technical drawings - Conventional representation of gears (ISO 2203:1973)

Overview

SIST EN ISO 2203:1998, titled Technical Drawings - Conventional Representation of Gears (ISO 2203:1973), is an international standard developed by the International Organization for Standardization (ISO) and adopted by the European Committee for Standardization (CEN). This standard establishes uniform conventions for the graphical representation of the toothed portions of gears-including worm gearing and chain wheels-in technical drawings. It applies to both detailed drawings of individual gears and assembly drawings showing gear pairs.

One fundamental principle specified by the standard is that gears, except in axial section, are drawn as solid parts without visible teeth, but with the pitch surface indicated by a thin long dash-and-dot line (long chain line). For consistency, all figures use first angle projection, supporting clarity and standardized communication among engineers and manufacturers worldwide.

Key Topics

• Scope and Applicability
  EN ISO 2203 covers the conventional graphical representation of toothed gears, worm gears, and chain wheels in mechanical engineering drawings. It applies to detail drawings (single gears) and assembly drawings (gear pairs).

• Graphical Representation Rules

  • Gears are typically shown as solid parts without teeth except in axial section views.
  • The pitch surface must be represented by a thin long chain line, visible even in concealed or sectional views.
  • In views normal to the gear axis, the pitch circle or median pitch circle is drawn.
  • In views parallel to the axis, the pitch surface is delineated with a contour line extending on each side.

• Teeth Representation
  Teeth are not generally detailed in unsectioned views but can be shown as thin continuous lines if needed. For precise specification of tooth profiles or to indicate tooth position or ends, one or two teeth may be drawn as thick continuous lines.
  The direction of teeth on helical or spiral gears is indicated using specific thin continuous line symbols.

• Assembly Drawing Conventions
  The standard mandates clear representation of meshing gears without unnecessary hidden lines, except where one gear physically obstructs another. Extended pitch surface lines are used for bevel gears in assembly. Various gear engagements-such as cylindrical, bevel, worm, and rack engagements-have defined depiction methods.

Applications

SIST EN ISO 2203:1998 is essential in fields requiring accurate technical communication involving gears:

• Mechanical Engineering Design
  Ensures precise and uniform depiction of gear components on engineering drawings, facilitating better design review, manufacturing, and maintenance processes.

• Manufacturing and Quality Control
  Enables machinists and quality inspectors to understand gear specifications and tolerances through standardized drawings.

• Automotive and Aerospace Industries
  Critical for assembly and maintenance documentation where multiple types of gearing are used.

• Education and Technical Training
  Provides a reference framework for students and professionals learning conventional gear drawing methods.

• Technical Documentation and CAD Modeling
  Supports interoperability between manual drafting standards and CAD systems by specifying conventional graphical elements.

Related Standards

• ISO 128 – General principles of presentation in technical drawings which complement the gear-specific conventions in EN ISO 2203.
• ISO 6410 – Technical drawings - Screw threads representation, often related when gear shafts and assemblies are involved.
• ISO 7010 – Graphical symbols used for safety information but sometimes used in gear-related safety documentation.
• ISO 5456 – Projection methods used in technical drawings aligning with the first angle projection specified in ISO 2203.
• Other Gear Standards (ISO 1328, ISO 21771) – Specify gear geometry, tolerances, and inspection methods, which rely on EN ISO 2203 for graphical representation.

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Keywords: technical drawings, gear representation, standard gears drawing, ISO 2203, EN ISO 2203, gear assembly drawings, worm gearing, chain wheels, mechanical engineering drawings, pitch circle, tooth profile, first angle projection, gear teeth direction, bevel gears representation.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Technische Zeichnungen - Darstellung von Zahnrädern (ISO 2203:1973)Dessins techniques - Représentation conventionnelle des engrenages (ISO 2203:1973)Technical drawings - Conventional representation of gears (ISO 2203:1973)21.200GonilaGears01.100.20Konstrukcijske risbeMechanical engineering drawingsICS:Ta slovenski standard je istoveten z:EN ISO 2203:1997SIST EN ISO 2203:1998en01-maj-1998SIST EN ISO 2203:1998SLOVENSKI
STANDARD
INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION l EXfiYHAPO,llHAB OPrAHH3ALU+iR n0 CfAHAAFIX3AU[HH .ORGANISATION INTERNATIONALE DE NORMALISATION Technical drawings - Conventional representation of gears First edition - 1973-03-15 UDC 744.4 : 621.83 Descriptors : drawings, engineering drawings, gears, chain wheels, representation. Ref. No. IS0 2203-1973 (E) Price based on 6 pages SIST EN ISO 2203:1998

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 : Australia Austria Belgium Canada Chile Czechoslovakia Denmark Egypt, Arab Rep. of France Germany Greece Hungary India Ireland Israel Italy Japan Korea, Dem.P.Rep. of Korea, Rep. of Netherlands New Zealand Norway No Member Body expressed disapproval of the document. Portugal Romania South Africa, Rep. of Sweden Switzerland Turkey United Kingdom U.S.A. U.S.S.R. 0 International Organization for Standardization, 1973 l Printed in Switzerland. SIST EN ISO 2203:1998

INTERNATIONAL STANDARD IS022034973 (E) Technical drawings - Conventional representation of gears 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 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, even i
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