A cylindrically-shaped headed item, having circular or longitudinal groove(s).
NSN 4140-01-552-0304
NSN 2925-01-501-1104
NSN 6220-00-812-0515
NSN 6110-00-583-9821
NSN 6105-00-699-9186
NSN 6685-01-296-1848
NSN 6650-01-643-9613
NSN 5915-00-396-8087
NSN 5998-01-501-5360
NSN 5990-01-116-2181
NSN 5945-01-445-6081
NSN 5945-01-401-5323