TS EN ISO 13715

TS EN ISO 13715 is a technical drawing standard for indicating and dimensioning edges of undefined shape in technical product documentation. It addresses situations where the exact edge geometry is not fully defined in advance, so the drawing needs a clear way to express the permitted edge condition and its representation.

What an undefined edge means

In mechanical and product drawings, an edge is not always given as a precise chamfer, radius, or break edge. Depending on manufacture, the edge may remain sharp, be rounded, be broken, or otherwise vary in condition. The purpose of ISO 13715 is to manage that ambiguity in drawing language so the designer and manufacturer read the same technical intent.

The standard also specifies the proportions and dimensions of the graphical symbols used for edge indication. This helps keep the visual notation consistent across organisations and CAD-based documentation systems. Where a geometrically defined edge is required, for example a clearly stated 1 × 45° chamfer, the general dimensioning principles of ISO 129-1 apply instead.

Why it matters in practice

• Provides a consistent way to show edges whose exact geometry is not fully defined
• Helps reduce misinterpretation between design, drafting, and manufacturing
• Keeps graphical symbols dimensionally consistent
• Works alongside general dimensioning rules when a precise edge geometry is needed