EN ISO 2203:1997

• Abstract:

  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.

• Status: Published
• Publication Date: 21-Oct-1997
• Withdrawal Date: 29-Apr-1998
• ICS: 01.100.20 - Mechanical engineering drawings
• ICS: 21.200 - Gears
• Technical Committee: CEN/SS F01 - Technical drawings
• Drafting Committee: CEN/SS F01 - Technical drawings
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 28-Jan-2002
• Completion Date: 28-Jan-2002
• Ref Project: SIST EN ISO 2203:1998 - Technical drawings - Conventional representation of gears (ISO 2203:1973)

Overview

EN ISO 2203:1997 sets out standardized methods for the conventional representation of gears on technical drawings. Published by CEN, this standard is equivalent to ISO 2203:1973 and provides guidance for depicting the toothed portions of gears, including worm gearing and chain wheels, in both detail and assembly drawings. Its principles promote clarity, accuracy, and consistency in mechanical engineering documentation, which is crucial for manufacturing, quality control, and international collaboration.

Key Topics

• General Principles for Gear Representation

  • Gears are drawn as solid parts without teeth in unsectioned views.
  • The pitch surface is indicated by a thin, long dash-and-dot line.
  • All figures use first angle projection for uniformity.

• Detail Drawings (Individual Gears)

  • Outlines the depiction of contours and edges as solid forms bounded by the tip surface.
  • Specifies representation of axial sections, typically showing two diametrically opposed teeth.
  • Advises on using thin continuous lines for tooth profiles when needed and thick continuous lines for special cases (e.g., defining ends or positions).

• Pitch Surface and Teeth Direction

  • The pitch surface must always be shown, even in concealed or sectional views.
  • Direction of gear teeth (helical, double helical, spiral) is depicted with distinct line patterns, described in standard tables.

• Assembly Drawings (Gear Pairs)

  • All rules for individual gears also apply to gear assemblies.
  • For bevel gears, pitch surface lines are extended to intersection points of axes.
  • Provides guidelines on how to represent gear pairs, including cases of engagement, overlapping, or concealment.

Applications

• Mechanical Engineering Drawings

  • Ensures uniform understanding of gear features among design, production, and quality teams.
  • Facilitates efficient communication of gear specifications and arrangements in documentation.

• Manufacturing and Inspection

  • Supports machinists and inspectors in reading and producing gears correctly.
  • Reduces ambiguity in drawings, lowering the risk of manufacturing errors or misinterpretations.

• International Collaboration

  • Promotes compatibility across borders by standardizing gear drawing conventions.
  • Essential for companies involved in export, contract manufacturing, or multinational projects.

• Education and Training

  • Used as a reference in engineering education for teaching best practices in technical drawing.
  • Helps standardize training materials for gear design and representation.

Related Standards

• ISO 128 - General principles of presentation in technical drawings.
• ISO 129 - Dimensioning principles for drawings.
• ISO 406 - Representation of gear tooth proportions.
• ISO 21771 - Gear terminology and definitions.
• ISO 1122 - Vocabulary of gear terms.

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By adhering to EN ISO 2203:1997, design and engineering teams ensure clear, reliable, and internationally recognized gear representations in technical drawings. Using this standard supports the accuracy of gear communication throughout the product development process, from initial design to final inspection. For organizations working with gears across different industries, implementing this standard is a key step toward enhancing quality, reducing misunderstandings, and streamlining engineering workflows.

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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