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 6685-01-634-0611
NSN 6610-00-386-4745
NSN 5935-00-067-6232
NSN 5910-01-063-4048
NSN 6105-00-446-2971
NSN 6105-01-398-1674
NSN 6320-00-139-1090
NSN 6150-01-313-0323
NSN 5835-01-297-1909
NSN 5985-00-050-2619
NSN 6110-01-272-1864
NSN 5910-01-231-3270