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 4140-01-423-9453
NSN 5990-01-632-0969
NSN 6220-00-276-8681
NSN 6685-01-539-5808
NSN 6610-00-888-3190
NSN 5999-00-699-5476
NSN 6620-00-916-3134
NSN 5985-01-591-4775
NSN 5998-01-624-7996
NSN 4140-01-057-4152
NSN 5996-01-472-2112
NSN 5945-00-553-9886