✅ If you are a student, check if your university library has a subscription to a standards database (e.g., ASTM Compass, DIN Media). Many institutions provide free downloads.
: For external threads, the undercut diameter is smaller than the thread's minor diameter to ensure clear tool exit and flush assembly.
(Transition Length): The total length including the angled chamfer leading back to the full thread.
I can provide the precise dimensions you need for your CAD model. Share public link din 76a pdf
The standard is divided into different forms depending on the application:
For internal threads:
However, based on the numbering pattern, you are most likely looking for one of the following three standards. This guide will help you identify the correct document and how to find it. ✅ If you are a student, check if
DIN 76‑1 is an essential standard for anyone designing, manufacturing, or inspecting ISO metric threaded components. By providing clear, harmonised dimensions for thread run‑outs and undercuts, it ensures that bolts, screws, and internal threads can be produced reliably and assembled without stress or interference. The standard has evolved over nearly a century, with the 2024‑11 draft representing the latest step in its continuous improvement.
When creating engineering drawings, you do not need to manually draw every detail of the undercut if you utilize standard callouts. Drawing Symbols
(Note: DIN 76 also defines Forms C and D, but these are for internal threads such as blind tapped holes, where the groove diameter is machined larger than the nominal diameter.) Understanding DIN 76 Form A Geometry (Transition Length): The total length including the angled
The DIN 76A standard is widely used in various industries, including:
Are you designing or internal threads (nuts/blocks) ?