The item is a flight safety critical aircraft part (fscap)
A nut having 6 flat sides and an integral washer which extends beyond the flats or periphery. An integral feature is incorporated for locking on the threads of a mating member.
Classification: Nuts of iron or steel
NSN 6610-00-144-7036
NSN 5998-01-511-5605
NSN 5960-01-015-7331
NSN 5915-01-293-0070
NSN 5945-01-436-0309
NSN 5985-01-401-5387
NSN 6320-00-336-9123
NSN 6610-00-186-9180
NSN 6645-01-385-7033
NSN 5996-01-374-0024
NSN 5935-00-396-3151
NSN 6110-01-633-9660