The NAS1149C0563R 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 interchangeable with AN960C516, and is commonly used as its NAS-series replacement in certified aviation hardware systems.

This washer is designed for 5/16-inch fasteners and helps ensure even load distribution, reducing stress concentration and preventing deformation of aluminum or steel components in structural joints. It is widely used in airframe assemblies, brackets, equipment mounting, and general aircraft maintenance applications where reliability and dimensional compliance are required.

Manufactured from corrosion-resistant steel (typically 18-8 stainless or equivalent per spec), it provides good durability and resistance to vibration, moisture, and environmental exposure in aviation service conditions. NAS1149 and AN960 washers share the same functional role, with NAS1149 representing the updated specification standard in many applications.

Key features include:

NAS1149C0563R aerospace flat washer
100 pcs maintenance pack
Alternative to AN960C516
Used for load distribution in bolted joints
Protects surfaces from wear and deformation
Designed for 5/16-inch aircraft fasteners
Corrosion-resistant steel construction (18-8 / equivalent)
Suitable for vibration and cyclic load environments
Standard NAS1149 series aircraft hardware
Direct replacement per aerospace specifications