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 6150-01-207-7305
NSN 5990-01-043-3400
NSN 4140-01-015-0124
NSN 5998-01-377-2497
NSN 5905-01-029-3864
NSN 6645-00-166-7926
NSN 5910-01-141-2715
NSN 6645-01-426-0206
NSN 4140-00-097-0167
NSN 5998-01-397-2163
NSN 5998-01-463-7931
NSN 5965-01-581-2164