While "Tabella Gola" translates to "Groove Table," the reference to specifically points to the international standard for "Fasteners — Product design rules for tapping screws and metal drive screws."

Per aiutarti a trovare esattamente la dimensione che ti serve, potresti dirmi:

is the Italian adoption of the international standard ISO 4755:1983 – Fasteners – Bolts, screws and studs – Undercuts for metric threads . It replaces older national standards (e.g., UNI 4749) and aligns with modern ISO thread systems (e.g., ISO 68-1, ISO 261, ISO 965).

The undercut serves three primary functions:

: The alignment with ISO standards facilitates international trade and collaboration, as products and documents produced under this standard are easily understood and accepted globally.

: Solo filettature metriche ISO esterne (serie M).

Note: $l_p$ (Point Length) is often roughly 2 to 3 times the pitch of the thread.