ISO/TS 128-71:2010

Technical product documentation (TPD) - General principles of presentation - Part 71: Simplified representation for mechanical engineering drawings

ISO 128-71:2010 specifies general principles and basic methods for the application of the simplified representation on mechanical engineering drawings.

Documentation technique de produits (TPD) — Principes généraux de représentation — Partie 71: Représentation simplifiée applicable aux dessins industriels

General Information

• Status: Published
• Publication Date: 18-Aug-2010
• ICS: 01.100.20 - Mechanical engineering drawings
• 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: 31-Oct-2024
• Completion Date: 13-Dec-2025

Overview - ISO/TS 128-71:2010 (Simplified representation for mechanical engineering drawings)

ISO/TS 128-71:2010 is a Technical Specification within the ISO 128 series for Technical Product Documentation (TPD). It specifies general principles and basic methods for applying simplified representation on mechanical engineering drawings. The aim is to make drawings easier to read and produce (manually and by CAD) while ensuring they do not cause misunderstanding. The document complements the complete representation rules of ISO 128 and related standards.

Key topics and technical requirements

• Scope and purpose
  • Defines when and how simplified representations may replace full geometric detail on mechanical drawings without loss of clarity.
  • Emphasises that simplified representation must never lead to misunderstanding or equivocation.
• Core principles
  • Simplification shall not cause ambiguity.
  • Simplified views should highlight the whole effect and improve readability.
  • Methods must consider manual, CAD and microcopy drawing requirements.
• Basic methods allowed
  • Reducing repeated structure detail: show one or a few identical features (teeth, grooves, fasteners) and indicate the total number rather than drawing every instance.
  • Omitting unnecessary views/sections: leave out views or sections that do not add information.
  • Simplifying element detail: depict bodies of revolution with circumferences, use centre lines for repeated groups, show pipes as centre-lines with end details, or present standard parts in outline.
• Illustrative examples
  • Use of circles for projections of slightly inclined arcs (≤ 30°).
  • Permitting simple sections not to be hatched.
  • Allowing local sections on principal views if identified.
  • Omitting small features such as chamfers, ribs or knurls in assembly views when not necessary.

Practical applications

• Reducing drawing complexity and production time for assemblies and repetitive components.
• Streamlining CAD libraries and technical documentation for:
  • Mechanical design offices
  • Manufacturing engineering
  • Assembly and maintenance manuals
  • Technical illustrators and PDM/PLM documentation teams
• Improving clarity in high-level assembly drawings while preserving necessary manufacturing or inspection information.

Who should use this standard

• Mechanical engineers, CAD drafters, technical authors and document controllers responsible for creating engineering drawings and assembly documentation.
• QA and manufacturing personnel who rely on consistent presentation of drawings.
• Standards committees and organizations harmonizing internal drawing practices.

Related standards

• ISO 128 series (general principles of presentation): ISO 128-20, -30, -40, -50, etc.
• ISO 129-1 (dimensions and tolerances - general principles)
• ISO 6411 (simplified representation of centre holes)

Keywords: ISO/TS 128-71:2010, simplified representation, mechanical engineering drawings, technical product documentation, ISO 128, CAD drawing standards.

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 128-71
First edition
2010-09-01
Technical product documentation
(TPD) — General principles of
presentation —
Part 71:
Simplified representation for mechanical
engineering drawings
Documentation technique de produits (TPD) — Principes généraux de
représentation —
Partie 71: Représentation simplifiée applicable aux dessins industriels

Reference number
©
ISO 2010
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ii © ISO 2010 – All rights reserved

Contents Page
Foreword .iv
Introduction.vi
1 Scope.1
2 Terms and definitions .1
3 General principles and basic methods of simplified representation.1
3.1 Principles.1
3.2 Basic methods .2
4 Examples.2

Foreword
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(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
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The main task of technical committees is to prepare International Standards. Draft International Standards
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In other circumstances, particularly when there is an urgent market requirement for such documents, a
technical committee may decide to publish other types of document:
⎯ an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in
an ISO working group and is accepted for publication if it is approved by more than 50 % of the members
of the parent committee casting a vote;
⎯ an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical
committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting
a vote.
An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a
further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is
confirmed, it is reviewed again after a further three years, at which time it must either be transformed into an
International Standard or be withdrawn.
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/TS 128-71 was prepared by Technical Committee ISO/TC 10, Technical product documentation,
Subcommittee SC 6, Mechanical engineering documentation.
ISO/TS 128 consists of the following parts, under the general title Technical product documentation (TPD) —
General principles of presentation:
⎯ Part 1: Introduction and index
⎯ Part 20: Basic conventions for lines
⎯ Part 21: Preparation of lines by CAD systems
⎯ Part 22: Basic conventions and applications for leader lines and reference lines
⎯ Part 23: Lines on construction drawings
⎯ Part 24: Lines on mechanical engineering drawings
⎯ Part 25: Lines on shipbuilding drawings
iv © ISO 2010 – All rights reserved

⎯ Part 30: Basic conventions for views
⎯ Part 34: Views on mechanical engineering drawings
⎯ Part 40: Basic conventions for cuts and sections
⎯ Part 44: Sections on mechanical engineering drawings
⎯ Part 50: Basic conventions for representing areas on cuts and sections
⎯ Part 71: Simplified representation for mechanical engineering drawings [Technical Specification]
The presentation of shipbuilding drawings is to form the subject of a future part 15.
...