Hammer Drive Rivets These are very tiny rivets available in round head and are brightly zinc plated. They have a peculiar type of concentric threading to give a very firm grip and the threading is not completed till the length of the screw so as to give a riveting position on the base. They are available in very small sizes the diameter which ranges from 1 mm to 4 mm and length from 3.2 mm up to 13 mm. They are used extensively to affix labels or name plates on any metal or fibre. They are to be riveted and cannot be drilled or tapered in any affixation.