Din 76-a Pdf Better Jun 2026

When a screw or a bolt is manufactured, there needs to be a small groove or relief cut at the end of the thread so the threading tool can exit cleanly without hitting a shoulder. This allows the nut to screw all the way down. DIN 76 defines the dimensions and shapes of these undercuts.

Short undercut for external threads (used when space is limited).

Standardization documents are protected by copyright and generally must be purchased. You can find the full, current version of at these official retailers: DIN Media (Beuth Verlag): The Official DIN 76-1 Source . Accuris (formerly IHS): Offers DIN 76-1 PDF Downloads .

It is common to confuse DIN 76-A with other international standards. Here is a quick comparison: din 76-a pdf

: Technical summaries and older versions of the standard (such as the 2004-06 edition) are often hosted on Scribd or CourseHero . Key Technical Breakdown

A gradual taper where the thread fades into the blank diameter.

| | Product Details | Pricing & Availability | | :--- | :--- | :--- | | DIN Media (Official Publisher) | Directly from the source: DIN Media Standards Solutions . Available in German or English, PDF or hardcopy. | The English PDF version is listed from €52.20 EUR (incl. VAT). | | ANSI Webstore | The official standards distributor in the US: ANSI Webstore . | Pricing is in USD and can be found on the website. | | Intertek Inform | A global distributor for professional standards. Intertek Inform holds multiple editions of the standard, including the new one. | Pricing varies and is available upon request on the site. | When a screw or a bolt is manufactured,

| Thread pitch ( P ) (mm) | Undercut length ( g_2 ) (approx.) | Undercut diameter | Transition radius ( R ) | Relief angle | |--------------------------|--------------------------------------|--------------------|--------------------------|--------------| | 0,2 | 0,7 mm | 0,3 mm | 0,1 | 30° | | 0,25 | 0,9 mm | 0,4 mm | 0,12 | 30° | | 0,3 | 1,05 mm | 0,5 mm | 0,16 | 30° | | 0,35 | 1,2 mm | 0,6 mm | 0,16 | 30° | | 0,4 | 1,4 mm | 0,7 mm | 0,2 | 30° | | 0,5 | 1,75 mm | 0,8 mm | 0,2 | 30° | | 0,6 | 2,1 mm | 1,0 mm | 0,4 | 30° | | 0,7 | 2,45 mm | 1,1 mm | 0,4 | 30° | | 0,75 | 2,6 mm | 1,2 mm | 0,4 | 30° | | 0,8 | 2,8 mm | 1,3 mm | 0,4 | 30° | | 1,0 | 3,5 mm | 1,6 mm | 0,6 | 30° | | 1,25 | 4,4 mm | 2,0 mm | 0,6 | 30° | | 1,5 | 5,2 mm | 2,3 mm | 0,8 | 30° | | 1,75 | 6,1 mm | 2,6 mm | 1,0 | 30° | | 2,0 | 7,0 mm | 3,0 mm | 1,0 | 30° | | 2,5 | 8,7 mm | 3,6 mm | 1,2 | 30° | | 3,0 | 10,5 mm | 4,4 mm | 1,6 | 30° | | 3,5 | 12,0 mm | 5,0 mm | 1,6 | 30° | | 4,0 | 14,0 mm | 5,7 mm | 2,0 | 30° | | 5,0 | 17,5 mm | 7,0 mm | 2,5 | 30° | | 6,0 | 21,0 mm | 8,3 mm | 3,2 | 30° |

The English translation is prepared by the DIN language service; however, the standard notes that “in case of doubt, the German‑language original shall be considered authoritative.”

The key takeaway is that . ISO 3508:1976 covered only thread run‑outs, and ISO 4755:1983 covered only undercuts for external threads. DIN 76‑1 covers both run‑outs and undercuts for both external and internal threads , making it a one‑stop reference for metric thread‑relief design. Short undercut for external threads (used when space

For a bolt, the undercut diameter must be smaller than the thread's minor diameter. For a hole, the relief groove diameter must be larger than the nominal diameter.

🔩 Engineering Resource: Understanding DIN 76-A Thread Undercuts