BlueSpot 100PCE Nut Rivets (M3 - M6) The BlueSpot 100PCE Nut Rivets (M3 - M6) are designed to be used with a nut riveter to place permanent threads in pre drilled holes when fixing two materials together. Manufactured from carbon Steel and zinc Plated Package Contents 25 x M3, 25 x M4, 25 x M5 & 25 x M6.