Din 76-a Pdf __exclusive__ Jun 2026

Disclaimer: This post is for informational purposes. Always purchase the official standard for legal manufacturing compliance.

Form A remains the default "normal" specification. If a drawing simply says "Undercut per DIN 76" without specifying a letter, engineering protocol generally defaults to Form A. Summary for Implementation din 76-a pdf

Note: $d$ is the major diameter of the thread. Disclaimer: This post is for informational purposes

| Thread Size | Thread Pitch P (mm) | Undercut Width a (mm) | Run-out length R (mm) | Undercut Diameter d₁ (mm) | |-------------|----------------------|------------------------|------------------------|-----------------------------| | M3 | 0.5 | 0.8 | 1.2 | 2.2 | | M4 | 0.7 | 1.0 | 1.6 | 3.0 | | M5 | 0.8 | 1.2 | 1.8 | 3.9 | | M6 | 1.0 | 1.5 | 2.2 | 4.7 | | M8 | 1.25 | 1.8 | 2.7 | 6.4 | | M10 | 1.5 | 2.2 | 3.2 | 8.2 | If a drawing simply says "Undercut per DIN