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 6610-01-027-1641
NSN 5925-01-606-1345
NSN 4140-01-394-8046
NSN 5910-01-628-8058
NSN 6320-00-261-9136
NSN 6105-01-514-2294
NSN 6220-00-577-3435
NSN 5996-00-277-7384
NSN 6645-00-337-8276
NSN 5910-01-051-2487
NSN 6620-01-038-5801
NSN 5965-01-445-3564