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 6240-00-717-0844
NSN 6135-01-079-7852
NSN 4140-00-403-7367
NSN 5996-01-400-3558
NSN 5950-01-403-2852
NSN 5925-00-647-3469
NSN 6145-00-759-6745
NSN 5990-01-328-9846
NSN 5855-00-058-1293
NSN 6240-01-225-0037
NSN 5960-00-892-0990
NSN 5990-00-067-6791