Overview
EN ISO 13715:2019 (identical to ISO 13715:2017) defines rules for indicating and dimensioning edges of undefined shape in technical product documentation. It specifies the graphical symbols, their proportions and placement on drawings, and how to control allowable deviations such as undercut (material removed) and passing (excess material, e.g., burrs or flash). For geometrically defined edge shapes (for example 1 × 45°), the general dimensioning principles of ISO 129‑1 apply.
Key topics
- Scope and terminology
- Clear definitions for edge of undefined shape, undercut, and passing.
- Basic graphical indication
- Standard symbol for undefined edges (proportions provided in Annex A).
- Symbols must be readable from the bottom of the drawing.
- Type of edge
- Use of symbol elements +, -, or ± to indicate permitted passing, required removal (undercut), or both (± only with size indication).
- Size (limits)
- How to indicate maximum deviations (single positive value implies zero lower limit; single negative implies zero upper limit).
- Procedure for specifying upper and lower limit deviations when both are required.
- Direction and location
- Rules for indicating direction of passing or undercut and for locating the basic symbol on individual edges, limited areas, or generally on a part.
- Supporting material
- Annex A: proportions and dimensions of graphical symbols.
- Annex B: examples of indication on drawings.
Practical applications
- Ensures consistent communication of edge conditions between design, manufacturing and inspection.
- Used when edge condition affects function or safety (e.g., sealing faces, mating parts, user-contact surfaces).
- Helps specify allowable burrs, flash, and shape deviations for casting, stamping, machining, molding and sheet-metal parts.
- Useful for CAD drafters, mechanical engineers, technical illustrators, quality inspectors, production planners and procurement/specification writers who create or interpret engineering drawings.
Who should use this standard
- Mechanical design and drafting teams producing engineering drawings.
- Manufacturers and toolmakers implementing tolerances and finishing operations.
- Quality and inspection personnel accepting parts against drawing requirements.
- Technical authors and standards committees harmonizing drawing practices across organizations.
Related standards
- ISO 129‑1 - general principles for dimensioning and tolerancing (applies when edge geometry is defined).
- EN ISO 13715:2019 is the CEN adoption of ISO 13715:2017 and is applicable across CEN member national standards bodies.
Keywords: EN ISO 13715:2019, ISO 13715:2017, edges of undefined shape, technical product documentation, edge indication, dimensioning, undercut, passing, graphical symbols, ISO 129‑1.
