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 5910-01-603-2070
NSN 5930-01-384-2232
NSN 5855-01-465-2245
NSN 5960-01-285-6521
NSN 5990-01-393-4808
NSN 5996-01-196-2042
NSN 6610-01-185-5832
NSN 5835-01-442-6482
NSN 6645-01-651-9562
NSN 6620-00-527-9280
NSN 6110-00-146-2114
NSN 6110-01-533-9494