2 New Diamond Coated Hole Saws. This is a new set of 2 diamond coated hole saws. These are great for filing glass, ceramics, tile, brick, plastics, wood, fiberglass, stone, rock carbide, gold, platinum, silver, metals or anything else that is hard. Longevity is assured as the diamond particles are electroplated onto the surface of the metal. Recommended for jewelers, lapidary, hobbies, crafts, modeling, home repair, etc. They can be used with a Dremel tool. Each hole saw measures approximately 1/4" (6.5 mm) in diameter with a 1/8" (3 mm) shank.