A nut having a sleeve portion on its under side, which can be crimped or clinched to hold the item in place when inserted in a hole.
NSN 6130-01-132-0199
NSN 7035-01-378-9325
NSN 5835-01-557-4914
NSN 5930-01-352-5428
NSN 2925-00-918-0859
NSN 6320-01-571-8974
NSN 5990-01-416-0362
NSN 5855-00-014-5008
NSN 6135-01-303-0295
NSN 5999-01-384-9028
NSN 5925-01-090-7994
NSN 5835-00-198-4936