A nut having an externally splined sleeve which holds it in position when forced into a hole of slightly smaller diameter.
NSN 5975-00-097-6282
NSN 6150-01-431-7001
NSN 5950-01-180-9011
NSN 6135-01-210-8715
NSN 5960-01-505-2426
NSN 5905-01-327-8157
NSN 4140-01-613-4492
NSN 6220-00-682-8292
NSN 5985-01-261-4274
NSN 6685-00-724-5998
NSN 5960-01-076-3936
NSN 5999-01-053-9931