The MS20002C4 Countersunk Washer is a military-standard aerospace washer designed for use in flush-mounted fastener applications where a smooth surface profile is required. It is typically used with countersunk screws or bolts to provide a clean aerodynamic or flush finish while still distributing load and protecting the mating surface.

This washer is widely used in aircraft structural assemblies, interior installations, and aerodynamic surfaces where protruding fasteners are not acceptable. It is supplied in a 100-piece pack for maintenance, repair, and production use.

Its primary features include:
Manufactured to MS20002 military aerospace standards
Countersunk design for flush fastener installations
Helps distribute load while maintaining a smooth surface
Suitable for aircraft structural and aerodynamic applications
Used with countersunk screws and bolts
Durable metal construction for aviation environments
Packaged in a 100-piece maintenance set
Compatible with aircraft assembly and repair operations

Washers like the MS20002C4 are widely used in aerospace applications because they support aerodynamic efficiency, improve surface finish quality, and maintain reliable fastening performance in structural assemblies.