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 5999-00-059-9461
NSN 5950-01-229-5600
NSN 5996-00-960-0103
NSN 5925-00-241-9774
NSN 5925-01-313-0205
NSN 5960-01-139-0293
NSN 6145-01-160-7658
NSN 6150-01-090-0946
NSN 6150-00-481-4763
NSN 5990-00-487-0135
NSN 5996-01-042-8554
NSN 5905-00-552-6639