Din 76-a Pdf Upd Jun 2026

When you cut a thread, the tool eventually has to stop. This creates a "run-out" (where the thread tapers off) or an "undercut" (a groove cut at the end of the thread to allow for clearance). Without these, the bolt's unthreaded shoulder would hit the tapped hole's edge before the bolt is fully seated.

It is designed to work seamlessly with DIN 13-1 , which defines the core ISO metric thread dimensions. Practical Resources din 76-a pdf

On a typical engineering drawing, you might see a note like: When you cut a thread, the tool eventually has to stop

It creates a groove at the end of a thread that is smaller than the minor diameter of the bolt. This allows a mating part (like a nut) to screw all the way to the shoulder of the bolt without interference from the incomplete threads that occur at the end of a threading tool's path. Dimensions: For Type A, the maximum width of the undercut ( ) is typically is the thread pitch). It is designed to work seamlessly with DIN

Among the various global standards, stands out as the leading technical guideline for these features. If you have searched for the term "DIN 76-A PDF" , you are likely an engineer, machinist, or quality control specialist looking for the exact dimensions and tolerances to ensure your threaded parts are both manufacturable and safe to use.

A groove at the end of the thread that allows the mating part to sit flush against a shoulder.

| Thread Pitch ($P$) | Width of Undercut ($a$) | Radius ($r_1$) | Undercut Diameter ($d_3$) | | :--- | :--- | :--- | :--- | | 1.0 mm | 2.0 mm | 0.5 mm | $d - 1.6$ | | 1.25 mm | 2.5 mm | 0.6 mm | $d - 2.0$ | | 1.5 mm | 3.0 mm | 0.8 mm | $d - 2.4$ | | 1.75 mm | 3.5 mm | 1.0 mm | $d - 2.8$ | | 2.0 mm | 4.0 mm | 1.0 mm | $d - 3.2$ | | 2.5 mm | 5.0 mm | 1.2 mm | $d - 4.0$ |