Overview
ISO 13715:2017 - Technical product documentation - Edges of undefined shape - Indication and dimensioning - specifies standardized rules for indicating and dimensioning edges that are not geometrically defined on the nominal model. The standard defines the graphical symbol, its proportions (Annex A), how to show size and direction limits, and conventions for individual, limited-area and general indications on engineering drawings. It also clarifies when to use ISO 129‑1 principles for geometrically defined edges (for example, 1 × 45°).
Keywords: ISO 13715:2017, edges of undefined shape, technical product documentation, edge indication, dimensioning, graphical symbols.
Key topics and technical requirements
- Scope and purpose: Controls deviations at edges that cannot be expressed by ideal geometry - e.g., undercut (material removed) and passing (excess material such as burrs or flash).
- Basic graphical indication: A standardized symbol (with proportions given in Annex A) must be readable from the bottom of the drawing. Additional information is placed in defined symbol areas.
- Type indication: Use symbol elements + (plus) for permitted passing, − (minus) for required undercut, or ± when both directions are allowed (± requires size specification).
- Size/dimensioning: Maximum deviations are indicated numerically after the symbol element. Single positive or negative limits imply the other limit is zero; two limits may be shown as upper/lower deviations.
- Direction and asymmetry: Rules for indicating direction of passing or undercut (single-direction and asymmetrical indications). Direction cannot be specified for non‑90° angles.
- Location conventions: Symbols may be applied individually (to a line or point), to limited areas (long-dashed-dotted line per ISO 128‑24), or generally for all edges (placed near title block or notes).
- Illustrative guidance: Annex B provides examples; figures in Clause 4 show application scenarios and terminology (undercut, passing, sharp edge).
Related references in the text: ISO 129‑1 (general dimensioning), ISO 128‑22, ISO 128‑24, ISO 1101.
Practical applications and users
ISO 13715:2017 is used to:
- Communicate required edge conditions on mechanical and product drawings.
- Specify acceptable burrs, flashes, undercuts and passes for manufacturing and inspection.
- Harmonize drawing interpretation between design, manufacturing, and quality control.
Primary users:
- Mechanical design engineers and CAD drafters
- Manufacturing engineers and machinists
- Quality inspectors and metrology labs
- Technical illustrators and standards coordinators
Related standards
- ISO 129‑1 - General dimensioning principles (for geometrically defined edges)
- ISO 128‑22 / ISO 128‑24 - Line types and drawing conventions
- ISO 1101 - Geometrical product specifications (used for “between” symbols)
Using ISO 13715 improves clarity of engineering drawings, reduces manufacturing errors related to edge conditions, and supports consistent quality inspection.