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 5960-01-169-1372
NSN 5835-00-949-3018
NSN 5990-00-630-6154
NSN 6105-00-404-6210
NSN 6220-00-216-7284
NSN 4140-01-067-8242
NSN 5999-01-377-9403
NSN 5910-00-107-2715
NSN 6645-01-156-6575
NSN 5925-01-364-0771
NSN 6620-01-447-6666
NSN 5945-00-887-3951