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 5855-00-586-6255
NSN 5905-00-642-0173
NSN 5960-00-872-5044
NSN 5910-01-170-0226
NSN 5985-01-020-3641
NSN 5990-01-035-6869
NSN 6610-01-511-0982
NSN 7035-01-226-2545
NSN 5835-00-853-7785
NSN 5960-01-487-4791
NSN 5835-01-610-5744
NSN 6650-00-296-4670