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 6135-01-529-3789
NSN 5835-01-568-7796
NSN 6135-01-366-9633
NSN 5930-01-470-4695
NSN 5998-01-364-6873
NSN 6150-01-152-1814
NSN 5855-01-536-1409
NSN 5930-01-415-1157
NSN 6645-01-091-9363
NSN 5998-00-419-6844
NSN 6645-01-408-6568
NSN 5935-01-409-2947