A nut having an externally splined sleeve which holds it in position when forced into a hole of slightly smaller diameter.
NSN 5855-01-449-5724
NSN 5985-00-049-7795
NSN 5965-00-407-4828
NSN 5910-01-465-8409
NSN 6610-01-551-0774
NSN 5945-01-058-8228
NSN 6620-00-431-3837
NSN 5998-01-510-6561
NSN 6150-00-068-3496
NSN 6240-00-082-1142
NSN 5975-00-185-5243
NSN 5960-00-802-6224