A nut having an externally splined sleeve which holds it in position when forced into a hole of slightly smaller diameter.
NSN 6240-01-381-6815
NSN 5855-01-147-6024
NSN 7035-01-302-5359
NSN 6645-01-128-0895
NSN 5925-01-134-4255
NSN 5985-00-244-1693
NSN 6645-01-579-2898
NSN 5835-01-245-8077
NSN 2925-01-519-3221
NSN 6650-01-431-8309
NSN 6320-01-340-4112
NSN 5960-01-279-0985