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 6240-01-091-3232
NSN 5905-01-396-0018
NSN 5975-01-104-5589
NSN 6645-01-432-7052
NSN 5999-01-252-8595
NSN 6650-01-338-3823
NSN 5895-00-962-5219
NSN 6685-01-391-4402
NSN 5965-01-008-8712
NSN 2925-00-139-3231
NSN 6220-00-911-0318
NSN 5999-00-877-8933