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 6685-00-985-5221
NSN 6135-01-483-5269
NSN 5965-01-083-5278
NSN 5950-00-801-7672
NSN 6610-00-408-4775
NSN 5905-01-023-1732
NSN 5999-01-118-8132
NSN 6320-00-149-7570
NSN 6685-00-295-8274
NSN 5910-01-104-1428
NSN 5996-01-353-9261
NSN 5999-01-508-6490