The Boeing Company
Washer assembly with seal for lightning-protection fasteners and method of manufacture

Abstract:

A washer assembly including a metallic washer and a polymer seal. The metallic washer defines a cylindrical void and an axis therethrough. The polymer seal is attached to the metallic washer and is positioned radially inward thereof. The polymer seal includes a lower seal portion positioned at least partially within the cylindrical void and defining a counter-bore, and an upper seal portion extending axially from the lower seal portion. The lower seal portion is configured to engage, at the counter-bore, a fastener to form a seal to reduce escape of energized particles. The upper seal portion is configured to engage a counter-bore of a counter-bored nut to form a seal inside the counter-bored nut to reduce escape of energized particles.