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 5855-00-256-5562
NSN 6110-00-443-4776
NSN 6645-01-225-4768
NSN 6685-01-158-4667
NSN 5895-00-103-7233
NSN 5950-01-266-8986
NSN 5835-01-130-8258
NSN 5895-01-257-1434
NSN 5998-00-848-9137
NSN 5950-01-281-6568
NSN 6145-01-121-4371
NSN 6130-01-194-5991