Overview
ISO 3098-2:2000 is the ISO standard that specifies the Latin alphabet, numerals and marks used in technical product documentation and drawings. It complements ISO 3098-0 (general prescriptions and dimensions) and focuses on the characters and signs applied to engineering drawings, CAD output and associated documents. The part addresses characters produced by lettering templates (trace-letters), freehand writing and other appropriate methods.
The standard emphasizes legibility and uniformity: letters should be formed so strokes meet or cross at approximately right angles to maintain a constant optical density and to avoid thickening at intersections. The publication includes illustrative examples of preferred scripts and orientations to guide consistent application.
Key Topics
- Character set: Latin alphabet letters, Arabic numerals and commonly used marks for technical documentation.
- Legibility rules: Guidance to avoid smudging and to preserve uniform stroke density, including stroke intersection principles.
- Writing methods: Application to trace-lettering, freehand and alternative marking techniques used on drawings and CAD systems.
- Illustrative examples: Sample alphabets and script styles showing upright and inclined lettering variants (examples A and B in upright and inclined forms).
- Reference to dimensions: For size and dimensional prescriptions, ISO 3098-0 provides the general requirements applicable to this part.
Applications
ISO 3098-2:2000 is intended for professionals who produce, review or consume technical drawings and product documentation where consistent lettering is critical. Typical applications include:
- Engineering and manufacturing drawings where readable annotations affect fabrication and inspection.
- CAD standards and template libraries to ensure text consistency across digital drawings.
- Technical documentation and assembly instructions requiring standardized alphanumeric notation.
- Quality control, archival of drawing records, and intercultural document exchange where a common lettering standard reduces misinterpretation.
Benefits include improved readability, fewer drawing errors related to text interpretation, and easier adoption of unified CAD lettering rules across teams and suppliers.
Related Standards
- ISO 3098-0 - General prescriptions and dimensions for lettering (referenced for character sizes and layout).
- ISO 3098-3 - Alphabet Greek (other script coverage within the series).
- ISO 3098-4 - Diacritic and special signs for Latin alphabet.
- ISO 3098-5 - CAD lettering for Latin alphabet, numerals and marks.
- ISO 3098-6 - Cyrillic alphabet.
ISO 3098-2:2000 forms part of the broader ISO 3098 series that standardizes lettering across scripts and methods, supporting consistent, legible technical product documentation for engineering and manufacturing workflows.