A cylindrically-shaped headed item, having circular or longitudinal groove(s).
NSN 5999-01-503-0252
NSN 5965-01-415-0872
NSN 5998-01-612-0934
NSN 6320-01-651-7476
NSN 5905-01-173-7525
NSN 5930-00-966-8628
NSN 5950-00-703-1686
NSN 6105-00-621-8878
NSN 5990-01-065-0492
NSN 6650-00-438-3983
NSN 6650-01-507-9636
NSN 5835-00-009-2862