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 4140-01-550-6540
NSN 2925-00-836-2323
NSN 6220-00-320-7408
NSN 5925-01-040-6733
NSN 5998-01-476-8753
NSN 6650-01-622-3550
NSN 6620-01-401-5356
NSN 6110-00-857-4274
NSN 5985-01-276-3919
NSN 6130-01-566-8942
NSN 6645-00-483-2981
NSN 5835-01-412-6901