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 5990-01-113-8121
NSN 6110-00-156-4307
NSN 6620-01-431-9176
NSN 6110-00-244-1354
NSN 6105-01-152-2800
NSN 5965-00-509-8769
NSN 6145-00-620-5922
NSN 6645-01-264-4093
NSN 6320-01-607-1491
NSN 6620-01-063-9054
NSN 6645-00-171-9639
NSN 7035-00-946-2642