Overview
ISO 128-1:2020 - Technical product documentation (TPD) - General principles of representation - Part 1: Introduction and fundamental requirements - provides the foundational rules for creating clear, consistent technical drawings (2D and 3D). It sets out the scope and structure of the ISO 128 series and defines the basic requirements that make drawings suitable for international exchange, manufacture and verification. The standard applies across mechanical engineering, construction, architecture and shipbuilding, and covers both manual and computer-based (CAD) technical drawings.
Key topics and requirements
- Fundamental principles: drawings must be unambiguous, clear, to scale (outlines proportional to the object), suitable for duplication, language independent, and compliant with standards in the ISO 128 series.
- Basic drawing entities: specifies required elements such as drawing sheet layout (ISO 5457), title block (ISO 7200 / ISO 9431), object representation (ISO 128 series), dimensioning (ISO 129), lettering (ISO 3098-1), part references (ISO 6433), units (ISO 80000), and protection notices (ISO 16016).
- Domain-specific guidance: references to geometrical product specification (GPS) standards for mechanical engineering (e.g., ISO 8015, ISO 1101, ISO 14405 series), construction (ISO 129-5, ISO 6284), and shipbuilding (ISO 129-4).
- Documentation rules: assembly drawings should include an item list per ISO 7573; release procedures and change documentation for drawings must be clearly recorded.
- Series structure: introduces other ISO 128 parts (line types, views/cuts/sections, shipbuilding representation, simplified mechanical representation, and an index).
Applications and who uses it
ISO 128-1 is used by:
- CAD engineers, drafters and technical illustrators creating 2D and 3D drawings
- Mechanical, construction and shipbuilding designers and architects
- Manufacturing engineers and quality/inspection teams verifying parts and assemblies
- Technical documentation authors, standards managers and product release coordinators
Practical benefits include consistent international communication of product definition, reduced misinterpretation in manufacturing, and standardised drawing output for plotting, copying and archiving.
Related standards (selected)
ISO 128-1:2020 is the starting point for anyone implementing or auditing technical drawing practices to ensure clarity, consistency and international interoperability in technical product documentation.