A cylindrical-shaped nut, the end opposite the bearing surface being designed with an internal socket or splines for use with an inserted wrench.
NSN 5975-01-308-5059
NSN 5998-01-201-2474
NSN 5965-01-472-1997
NSN 5910-01-553-4137
NSN 6650-01-115-7981
NSN 5990-00-461-5372
NSN 5990-01-084-0807
NSN 6220-01-061-6953
NSN 6130-01-463-0705
NSN 6610-00-710-3236
NSN 5999-00-450-3188
NSN 6610-00-261-8159