Flange Nut

Flange nuts are hex nuts with a built-in, non-spinning washer at the base. The integrated flange distributes clamping load evenly across the mounting surface, eliminating the need for a separate washer and simplifying assembly.

Applicable Standards

Standard	Description	Notes
DIN EN 1661 / DIN 6923	Hexagon flange nuts – metric series	DIN EN 1661 is the current European standard, superseding DIN 6923. Dimensions largely interchangeable; M10 across flats changed from 15 mm to 16 mm. Available in serrated or plain versions.
DIN 6926	Hexagon flange nuts with nylon insert – metric series	Prevailing torque locking type; nylon insert provides vibration resistance.
DIN 6331	Hexagon collar nuts (height 1.5 × thread diameter) – metric series	Plain flange, taller design for clamping applications requiring frequent assembly/disassembly.
ASME B18.16.6	Serrated hex flange locknuts and serrated nylon insert flange locknuts – inch series	Locking type; includes both all-metal and nylon insert configurations.
ASME B18.2.2	Square and hex nuts – inch series	Covers plain hex flange nuts (non‑locking) for general industrial use.