Din 76a Pdf =link= Direct

Variations utilized for exceptionally short thread runouts or specialized manufacturing setups where tight axial tolerances dictate alternate clearance shapes. Summary for Manufacturers

: It provides a clearance groove at the transition between the threaded section and the shoulder of a component.

: Specifies short thread undercuts for external threads (used when space or engagement length is limited). Form C & D : Apply to internal (female) thread undercuts. din 76a pdf

) will have a much wider and deeper undercut than an M12 fine thread (

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

To provide a standard, reliable termination for bolts, screws, and studs, ensuring that fasteners can seat properly without interference at the thread end.

A typical data sheet found within a DIN 76-A PDF provides specific dimensions tied strictly to the pitch ( Form C & D : Apply to internal (female) thread undercuts

I can provide the precise dimensions you need for your CAD model. Share public link