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 6135-01-357-0621
NSN 5985-01-298-2070
NSN 4140-01-431-6560
NSN 6240-01-383-7114
NSN 6130-00-184-8504
NSN 6130-01-207-0755
NSN 5895-00-224-4442
NSN 6610-00-099-4096
NSN 6220-01-508-5053
NSN 5915-01-233-3757
NSN 6145-01-434-3750
NSN 4140-01-555-8190