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 6130-01-474-6544
NSN 5999-01-649-7971
NSN 5915-01-359-2573
NSN 5910-00-344-4431
NSN 5990-01-434-7913
NSN 4140-00-419-0631
NSN 5930-00-202-9213
NSN 5998-01-394-4985
NSN 6135-01-492-5717
NSN 6135-01-204-3882
NSN 6110-00-731-9754
NSN 5960-01-481-3722