A nut having an externally splined sleeve which holds it in position when forced into a hole of slightly smaller diameter.
NSN 6320-01-631-7828
NSN 5965-00-840-8849
NSN 5998-01-258-3209
NSN 5935-01-497-1522
NSN 5915-01-633-9845
NSN 5960-01-406-4136
NSN 5905-00-780-8694
NSN 6650-01-115-2766
NSN 6610-00-632-6645
NSN 5996-00-186-8709
NSN 5910-01-572-5441
NSN 5965-00-247-4886