The STD-1411 nut is a standard aircraft-grade hex nut used in general aviation engine and airframe assemblies. It is part of the FAA “STD” (standard hardware) family and is commonly found in Lycoming engine installations and related airframe structures.

This nut has a 1/4-20 UNF fine thread and is used with matching AN/MS bolts or studs to secure engine components, accessories, brackets, and structural fittings. It is designed for reliable locking under vibration and cyclic loading conditions typical of aircraft operation.

Key features include:

Standard aviation hex nut (STD hardware series)
Thread: 1/4-20 UNF (fine thread)
Used in Lycoming and general aviation engine assemblies
Compatible with AN/MS bolts and aircraft studs
Designed for vibration resistance in flight environments
Typically made from cadmium-plated or corrosion-resistant steel
Used in engine, accessory, and airframe fastening applications
Approved for certified aircraft maintenance and overhaul work