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 5910-01-551-9189
NSN 5990-01-198-7953
NSN 5965-00-182-7928
NSN 6135-01-265-1384
NSN 6320-01-516-3836
NSN 5925-01-341-6758
NSN 5920-01-498-0847
NSN 5985-01-576-0468
NSN 6685-01-483-5970
NSN 5999-00-355-8853
NSN 6135-01-407-0594
NSN 5975-01-470-6551