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 5920-01-588-1028
NSN 5990-01-524-7744
NSN 6610-00-845-1070
NSN 5960-00-577-1512
NSN 6130-00-523-9210
NSN 6620-00-988-0976
NSN 6145-00-027-9852
NSN 4140-00-359-9351
NSN 6645-01-391-6492
NSN 5965-01-396-7508
NSN 6650-00-658-9627
NSN 5945-00-856-3301