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 6110-01-322-8378
NSN 6645-01-430-2420
NSN 7035-01-469-5854
NSN 5835-01-377-8972
NSN 5960-01-648-1872
NSN 6620-01-352-5640
NSN 6110-01-367-2165
NSN 5998-00-179-3958
NSN 5965-01-045-0247
NSN 6645-01-271-0248
NSN 6240-01-265-5039
NSN 6145-01-517-0333