Elliptical 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 5895-00-351-7463
NSN 5915-01-045-7358
NSN 6105-01-022-8693
NSN 5935-01-399-7270
NSN 5965-00-113-9748
NSN 6685-01-106-3210
NSN 5990-00-081-1266
NSN 5985-00-823-6302
NSN 5915-01-426-1338
NSN 5996-01-549-6387
NSN 5920-01-582-0388
NSN 5985-01-358-7541