The NAS1149F0663P is an aerospace-standard flat washer used in aircraft structures to distribute load under bolt or nut heads and protect mating surfaces from damage. It is functionally equivalent to AN960-616, and is widely used as its modern NAS-series replacement in certified aircraft hardware systems.

This washer is designed for 3/8-inch aerospace fasteners and helps ensure proper clamp load distribution, reducing stress concentration and preventing surface deformation in aluminum and steel assemblies. It is commonly used in airframe structures, landing gear attachments, and general aircraft maintenance applications where reliable fastening performance is required.

Manufactured to NAS standards, it is typically made from cadmium-plated steel (CRES variants also exist depending on specification), providing corrosion resistance and durability in vibration-heavy and environmentally exposed aviation conditions. The NAS1149 series is widely recognized as the direct successor to AN960 washers in many aerospace applications.

Key features include:

NAS1149F0663P aerospace flat washer
Equivalent / alternate to AN960-616
Used for load distribution in bolted joints
Protects surfaces from wear and deformation
Designed for 3/8-inch fasteners
Steel construction with cadmium corrosion protection
Suitable for airframe and structural assemblies
High resistance to vibration and cyclic loading
Standard NAS1149 series aircraft hardware
Direct replacement per aerospace specifications