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 6105-01-331-0609
NSN 5996-01-238-1041
NSN 6685-01-579-7358
NSN 6135-00-958-7981
NSN 5915-00-837-4460
NSN 6320-01-119-3935
NSN 6220-00-541-8515
NSN 6220-01-564-7080
NSN 6240-00-370-5862
NSN 6645-01-185-7684
NSN 5945-01-142-2182
NSN 5950-01-545-7911