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 4140-01-120-1622
NSN 5915-01-551-2657
NSN 5998-01-209-6715
NSN 5945-00-289-9859
NSN 5996-00-472-9157
NSN 5925-01-251-1342
NSN 6320-01-652-3806
NSN 6240-00-931-9654
NSN 6110-01-395-6574
NSN 4140-00-347-6807
NSN 6620-00-221-7526
NSN 6220-01-519-8385