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 5925-01-464-4551
NSN 6620-00-500-0041
NSN 5920-01-242-9208
NSN 5945-01-645-5881
NSN 6130-00-099-6528
NSN 5855-01-023-3727
NSN 6135-01-319-0623
NSN 5905-01-535-4322
NSN 6645-01-650-9189
NSN 6685-01-389-2790
NSN 5975-00-364-6919
NSN 5920-01-464-3863