Manufacturers suggested name is plug; material is stainless steel with stellite overlay
NSN 6135-01-441-0518
NSN 5920-00-614-4643
NSN 2925-00-265-7539
NSN 7035-01-012-2259
NSN 5920-00-294-0753
NSN 5960-01-412-0619
NSN 6610-00-553-5103
NSN 4140-00-696-4556
NSN 7035-01-330-3768
NSN 6620-00-190-3385
NSN 4140-01-517-8179
NSN 6610-00-927-2279