Din 76a Pdf May 2026

For a standard metric thread (M thread), the run-out length is defined as a function of the thread pitch (P). The core diameter increases from d3 (minor diameter of the thread) to d (nominal diameter of the shank) over a specific axial distance.

Typical formula (derived from DIN 76a):

Example for M10 x 1.5 (Pitch = 1.5mm):

1. Purpose
Defines standard shapes and dimensions for thread run-outs (where the thread fades into the shaft) and undercuts (grooves at the end of a thread) for metric ISO threads per DIN 13.

2. Thread run-out (Type A – no undercut)

3. Thread undercut (Type B – with undercut groove) din 76a pdf

| Pitch ( P ) (mm) | Width ( b ) (mm) | |--------------------|--------------------| | 0.2 – 0.5 | 0.5 – 1.0 | | 0.6 – 1.0 | 1.0 – 1.6 | | 1.25 – 1.75 | 1.6 – 2.5 | | 2.0 – 3.0 | 3.0 – 4.0 | | 3.5 – 5.0 | 5.0 – 6.0 |

4. Form F (fine undercut for high stress)

5. Designation example
Undercut DIN 76-1 – M12 – Form B
→ Metric thread M12 with undercut per DIN 76-1, type B.

To get the actual complete PDF file legally, you can:

If you meant DIN 76a from an older edition (pre-2000s), that content is superseded by DIN 76-1. For a standard metric thread (M thread), the

is a technical standard that defines the dimensions for thread run-outs thread undercuts

for ISO metric threads (conforming to DIN 13-1). The "76A" often refers to , which is the standard type for external thread undercuts. Core Details of DIN 76-1 (Form A)

: It specifies the geometry required for the end of a thread when it meets a shoulder or bearing face, ensuring proper clearance for mating parts and manufacturing tools. : This specific designation refers to a standard external thread undercut

. It is the default choice for external threads unless technical reasons require a shorter version (Form B). Dimensions : Key variables calculated based on the thread pitch ( ) include: : Diameter of the undercut. : Width (length) of the undercut. : Transition radius. Technical Warning

: Fasteners with a thread undercut do not meet the minimum breaking load requirements specified in DIN EN ISO 898-1 Accessing the PDF and Papers Example for M10 x 1

You can find detailed documentation and technical diagrams for this standard on several platforms: Standard Previews

: Short summaries and technical excerpts are available on sites like Official Purchase

: The full, authoritative PDF is typically purchased through Beuth Publishing (the official distributor for DIN standards). Technical Guides

: Manufacturers often provide abbreviated versions of these tables in their technical catalogs, such as the KIPP Standards Overview comparison table for the dimensions of different thread pitches under Din 76-1 | PDF | Screw | Metalworking - Scribd

DIN 76a is a German industrial standard (Deutsches Institut für Normung) that specifies the design of thread run-outs and thread undercuts for metric ISO threads according to DIN 13.

Released under the full title "Design of thread run-outs and thread undercuts for metric ISO threads according to DIN 13," this standard defines the geometric shapes, dimensions, and tolerances for: