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.
Open preview (PDF)Technical product documentation (TPD) — General principles of presentation — Part 71: Simplified representation for mechanical engineering drawings