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 6650-01-407-4653
NSN 6150-01-064-2779
NSN 5915-01-633-9845
NSN 6105-01-420-7561
NSN 5935-00-928-8221
NSN 6645-01-379-7725
NSN 5950-00-181-9285
NSN 6105-01-347-0070
NSN 5965-01-408-1303
NSN 5930-01-072-8964
NSN 5855-01-657-7657
NSN 5985-01-569-3770