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 5950-01-573-6434
NSN 5855-01-020-7982
NSN 6645-01-043-3179
NSN 5965-01-548-5359
NSN 5996-01-400-3558
NSN 6645-01-413-0515
NSN 5905-01-164-5453
NSN 6130-01-359-1712
NSN 6645-01-373-8860
NSN 5910-00-607-0125
NSN 5999-00-824-0226
NSN 4140-01-479-0283