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 6150-01-377-0520
NSN 5915-01-400-1989
NSN 5960-01-013-2587
NSN 5935-01-422-0783
NSN 6240-01-050-8306
NSN 5910-01-217-1636
NSN 5960-01-163-3847
NSN 6145-01-545-4784
NSN 5990-01-042-1984
NSN 6650-01-295-4411
NSN 5930-01-386-7181
NSN 5950-01-127-0351