A nut having an externally splined sleeve which holds it in position when forced into a hole of slightly smaller diameter.
NSN 5915-01-223-3087
NSN 5990-01-130-4959
NSN 5835-01-254-8584
NSN 7035-00-834-2090
NSN 2925-00-233-5644
NSN 6220-00-988-5311
NSN 5855-00-256-5562
NSN 5999-01-320-7887
NSN 6620-01-154-4209
NSN 6620-01-210-2538
NSN 5996-00-121-2914
NSN 6150-01-113-8553