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 6240-01-449-0746
NSN 5905-01-567-7263
NSN 7035-01-459-8268
NSN 5999-01-535-1599
NSN 6320-00-593-0379
NSN 6145-01-032-4557
NSN 6105-00-871-6960
NSN 5990-01-052-9343
NSN 6135-01-025-8109
NSN 5990-01-390-2177
NSN 5925-01-659-5117
NSN 6650-00-646-7288