) of the metric thread, rather than just the major diameter ( Key Geometric Parameters
The imperfect threads near the shoulder (called the thread runout) will prevent a mating female part (like a nut or a tapped block) from flushing perfectly against the shoulder.
Scribd Technical Library (for 2004/archived versions).
) if space permits, as it allows for easier machining and better tool clearance. Use the short width ( ) only when axial space is highly restricted. Finding a DIN 76-A PDF din 76-a pdf
: Public previews and technical summaries can often be found on platforms like Scribd .
The standard defines :
(Radius): The curvature at the base of the undercut to prevent sharp corners that lead to fatigue cracking. Table: Common DIN 76-A Dimensions (Partial) Thread Pitch (P) 📋 Types of Undercuts in DIN 76 ) of the metric thread, rather than just
To obtain an official, legally compliant copy of the DIN 76-1 PDF, you should visit authorized standards distributors such as (the official publisher of DIN standards) or the ISO Store .
Are you trying to decide between and Type B (short) for a tight assembly?
It allows the bolt head or nut to sit flush against the workpiece. Use the short width ( ) only when
) on every single threaded shoulder—which clutters the drawing—you can simplify the process by using a standard designation callout. You draw the simplified representation of the undercut and point to it with a leader line. Standard Callout Format The text on your drawing leader line should read:
Understanding this standard is critical for ensuring that threaded fasteners can be fully seated against a mating surface, preventing mechanical interference and ensuring structural integrity. 🛠️ What is DIN 76-A?
Note: $d$ is the major diameter of the thread.