It is designed to work seamlessly with DIN 13-1 , which defines the core ISO metric thread dimensions. Practical Resources
Precise rounding in the undercut helps distribute stress and prevents the fastener from snapping under load. Standard Classifications (Forms A, B, C, D) din 76-a pdf
You will rarely find a 100% free, official PDF of the current DIN standard due to copyright laws (DIN standards are sold to fund the organization). However, here is how to access the information: It is designed to work seamlessly with DIN
Legally, no. DIN standards are copyrighted technical documents. However, many reputable engineering reference handbooks (e.g., Machinery's Handbook , Roloff/Matek Maschinenelemente ) summarize the critical tables of DIN 76-A. For quick workshop reference, laminated summary charts are often available from third-party vendors. But for legally binding design work, you must purchase the official PDF. However, here is how to access the information:
For official documentation, you can purchase the full standard from DIN Media or Accuris Standards Store . Din 76-1 | PDF | Screw | Metalworking - Scribd
How to correctly label these features on technical drawings (e.g., DIN 76-A).