Eliptical locking feature id
A soft metal or nonmetal sleeve, designed to mate with a pin-rivet. it may include an external wrenching facility which breaks off at a perdetermined torque to form a head.
NSN 5910-01-068-7469
NSN 5945-01-214-2446
NSN 5910-00-761-3229
NSN 7035-00-541-8516
NSN 5990-00-917-4220
NSN 5985-00-079-8671
NSN 5855-00-879-7245
NSN 5990-00-908-0282
NSN 5935-01-382-6379
NSN 6620-00-273-8735
NSN 6130-01-554-5064
NSN 5905-01-049-4234