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 5930-00-423-7145
NSN 6685-01-226-1235
NSN 5965-01-431-8147
NSN 5998-00-333-6221
NSN 5990-00-269-2226
NSN 5985-00-054-5315
NSN 6135-01-210-8715
NSN 5950-00-777-8773
NSN 6320-01-116-3980
NSN 5999-01-159-8571
NSN 6685-01-408-9672
NSN 6220-01-421-3335