ISO 128-3:2022

Overview - ISO 128-3:2022 (Technical product documentation - Views, sections and cuts)

ISO 128-3:2022 defines the general principles for presenting views, sections and cuts in technical product documentation (TPD). It applies to a wide range of technical drawings - mechanical, electrical, architectural and civil engineering - and aligns with orthographic projection methods specified in ISO 5456-2. The standard also addresses reproduction requirements (including microcopying per ISO 6428) and provides field-specific rules in annexes for mechanical, building and construction drawings.

Key topics and technical requirements

• Selection of views: Use the most informative view as the principal view; limit the number of views to the minimum necessary to avoid ambiguity and unnecessary repetition.
• Projection methods: Principles for first‑angle and third‑angle orthographic projection are referenced and symbolized according to ISO conventions.
• Identification of views: Each view (except the principal/front view) is marked with a capital letter near a reference arrow; placement and orientation rules ensure consistent readability.
• Cuts and sections: Definitions for “cut” and “section” and rules for indicating cutting planes, identifying sections and referencing sectioned views.
• Partial and simplified views: Rules for partial views (to highlight features) and simplified representation of symmetrical parts to save space and clarify drawings.
• Graphical conventions: Hatching/section lining, shading/toning, thin sections, and treatment of adjacent sections and specific materials are covered (see Clause 7).
• Reproduction considerations: Guidance for drawing elements to remain legible when reproduced or microcopied, per ISO 6428.
• Annexed guidance: Normative and informative annexes supply graphical symbols (A), historical practices (B), and application rules for mechanical (C/D), building (E) and construction drawings (F).

Practical applications and intended users

ISO 128-3:2022 is used to ensure clear, unambiguous presentation of 2D views, sectional views and cuts across technical documentation workflows. Typical users:

• Mechanical, electrical and civil engineers
• CAD/BIM designers and drafters
• Technical illustrators and documentation specialists
• Architects and construction professionals
• Quality, manufacturing and assembly teams relying on consistent drawings

Benefits include improved cross-disciplinary communication, fewer manufacturing or construction errors, and consistent documentation for legal, procurement and regulatory use.

Related standards

• ISO 5456-2 - orthographic projection methods (referenced)
• ISO 16792 - views and sections for 3D models
• ISO 6428 - requirements for microcopying/reproduction
• ISO 128-2, ISO 128-15 - related parts of the ISO 128 series
• ISO 10209 - vocabulary for technical drawings

Keywords: ISO 128-3:2022, technical product documentation, views sections cuts, orthographic projection, first-angle, third-angle, engineering drawings, TPD, CAD documentation.