A headless fastener externally threaded on both ends with each threaded portion of one but not necessarily the same nominal diameter. It is designed to be locked in place by either a ring, lock, serrated or a ring, lock, keyed.
NSN 4140-00-135-3821
NSN 5835-01-512-4834
NSN 7035-01-048-2813
NSN 5965-01-421-9593
NSN 6610-00-211-3475
NSN 5920-01-286-2597
NSN 5998-01-052-2114
NSN 6610-00-516-4228
NSN 6135-01-412-0097
NSN 5920-01-526-2008
NSN 4140-00-170-5152
NSN 6150-01-093-3434