DIN 6923 is the prevalent European standard for Hexagon Flange Nuts. This integrated design combines a standard hex nut with a circular flange base, effectively acting as a built-in washer to distribute pressure over a larger surface area and prevent damage to the mating material.

These fasteners are highly effective for high-vibration applications and automated assembly lines. While the standard DIN 6923 typically refers to a smooth bearing surface, serrated versions (often designated as DIN 6923S) are widely utilized to provide enhanced locking capabilities against loosening.

The technical focus of DIN 6923 is the clamping force distribution. By eliminating the need for a separate washer, the flange nut reduces the number of components in an assembly and lowers the risk of human error during installation. The "Flange Diameter" ($d_c$) is engineered to cover oversized or slotted holes common in automotive and renewable energy structural frames.