If you have ever looked at a technical drawing and wondered, "Is that edge supposed to be sharp? How sharp is 'sharp'?" — you are not alone.
Enter . This standard is the universal language for defining the condition of undefined edges on technical drawings.
Simply put: It tells the machinist how to treat the "leftover" edges—those small intersections between two surfaces where no specific radius or chamfer is called out. din iso 13715
Disclaimer: This post is for informational purposes. Always refer to the latest official DIN ISO 13715 standard document for absolute compliance.
![Example symbol structure: A triangle-like figure with a line pointing to the edge, plus a numeric value.] If you have ever looked at a technical
Here is what the symbols mean:
In the world of precision manufacturing, assuming an edge is sharp can lead to burrs, injuries, and assembly issues. Conversely, assuming an edge is broken (chamfered or rounded) without a specification can lead to unnecessary machining costs. This standard is the universal language for defining
For sharp edges that must cut (e.g., cutting tools, scrapers), write: "Edge max R 0.05" or "Sharp edge permitted – handle with care" (though the latter is rare in modern standards). The Most Common Mistake Do not write: "Break all sharp edges." This is subjective. Does "break" mean 0.1 mm or 1.0 mm? It depends on who is reading.