Standard undercut for internal threads (tapped holes). Type D: Short undercut for internal threads. 📝 Design Considerations for Engineers
Tools like SolidWorks, McMaster-Carr, and TraceParts often have DIN 76-A geometries pre-configured in their fastener libraries.
Do you need help for a custom machined part? din 76-a pdf
Typically, you do not need to draw the exact geometry if you call out the standard. Use a note such as: 📥 How to Find a DIN 76-A PDF
Proper undercut geometry can reduce stress concentrations at the transition between the thread and the shank. 📏 Key Specifications in DIN 76-A Standard undercut for internal threads (tapped holes)
It provides a "run-out" area for the thread-cutting tool.
The standard provides a lookup table based on the thread pitch (). For any given pitch, DIN 76-A specifies three primary dimensions: Do you need help for a custom machined part
Short undercut for external threads (used when space is limited).