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 5998-01-491-6259
NSN 6685-01-286-1927
NSN 6650-01-317-2101
NSN 5930-00-407-2704
NSN 4140-00-249-5603
NSN 6610-00-100-1195
NSN 6320-01-089-9086
NSN 6240-01-036-7089
NSN 6220-00-012-3620
NSN 5855-00-100-9003
NSN 6130-00-413-1288
NSN 7035-01-413-6697