Barrel nuts minimize drilling and eliminate the need for long expensive bolts when attaching heavy structural members in high-tensile applications, such as hanging aircraft engines or attaching wings or tails to the fuselage. Barrel nut retainers are sheet metal parts that typically clip on barrel nuts to facilitate their installation in holes and alignment with mating bolts. Fabricated in advanced aerospace alloys, designs include floating or nonfloating, metallic lock or nonmetallic ring, tandem nuts with spreaders, spreaders that articulate, and barrel nuts with attached retainers or lanyards.
