Din — 76-a Pdf
. It is essential for ensuring that fasteners, like bolts and screws, can be screwed flush against a bearing surface and that the thread transitions do not create excessive stress concentrations. BAER Tools Core Purpose and Forms
How to correctly label these features on technical drawings (e.g., DIN 76-A).
A sharp corner creates a high-stress concentration point, which can lead to fatigue failure. DIN 76-A specifies a precise radius ( ) at the corners of the groove to distribute stress evenly. Reference Dimension Table for DIN 76-A din 76-a pdf
The standard defines the dimensions and design specifications for thread run-outs and thread undercuts for ISO metric threads. It ensures that threads terminate cleanly, preventing assembly issues like burrs or incomplete fits.
When looking at a DIN 76-A engineering drawing, you will encounter the following symbols: : Major diameter of the thread (e.g., M10, M12). : Thread pitch (e.g., 1.5mm). A sharp corner creates a high-stress concentration point,
DIN 76 is the overarching standard that defines thread undercuts and thread run-outs for ISO metric screw threads. The standard is divided into different forms depending on the application and whether the thread is external or internal.
| Feature | Dimension | Value (mm) | | :--- | :--- | :--- | | Thread Pitch | P | 1.5 | | Run-out length (x) | Short | 3.0 | | Run-out length (x) | Long | 4.5 | | Undercut width (b) | ~ | 3.2 – 3.7 | | Undercut bottom dia (d₁) | ~ | 8.0 | It ensures that threads terminate cleanly
Yes, the new 2025 edition specifically incorporates the optional dimension x3 for rolled threads on solid shanks. This is a key update that directly addresses modern manufacturing processes.
If you are using a non-standard thread or require specific quality controls, the callout can be expanded to include the exact thread pitch, but referencing the standard is usually sufficient for CNC machinists to look up the exact tooling offsets. Why Downloading the Official PDF Matters
The standard is divided into two main parts:
