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 5925-01-447-9767
NSN 5990-01-199-2846
NSN 5915-01-432-2491
NSN 5965-01-444-1322
NSN 5920-01-122-4181
NSN 5999-01-130-8911
NSN 5945-00-244-1579
NSN 6320-00-456-0836
NSN 5999-01-634-0576
NSN 6110-00-159-0755
NSN 5975-01-222-7158
NSN 6320-00-476-6898