A cylindrically-shaped headed item, having circular or longitudinal groove(s).
NSN 4140-01-317-3559
NSN 5915-01-139-0943
NSN 6130-01-039-7418
NSN 6620-01-216-4901
NSN 6220-00-971-8332
NSN 6220-00-383-7354
NSN 5855-01-582-7368
NSN 5835-01-056-9303
NSN 6685-01-252-6692
NSN 5920-01-131-9714
NSN 6240-01-305-0908
NSN 5975-01-189-3022