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 6220-01-646-0555
NSN 6240-00-079-0112
NSN 5930-01-634-0659
NSN 6320-00-925-0558
NSN 6685-00-626-4296
NSN 5920-01-426-8517
NSN 5999-01-281-5593
NSN 5960-01-486-8919
NSN 5960-01-370-4285
NSN 5990-00-548-6163
NSN 6620-01-128-4462
NSN 6130-01-167-8036