High-quality materials: The heavy-duty high-speed steel and bi-metal hole saw set is sturdy and suitable for repeated use. The hole saw base and HSS hole saw teeth are 8 mm thick and durable. Widely used: The drill bit set covers the most common hole saws on the market. The hole saw set is convenient for household projects when cutting holes through wood, Placoplâtre, acrylic panels, and thin metal. Sturdy case: The cutter set is well organized in a convenient plastic case. So you can work smoothly and you don't have to worry about pieces getting lost due to awkward storage. 19 Pieces Open Hole Saw Set: The set consists of 19mm, 22mm, 25mm, 29mm, 35mm, 38mm, 44mm, 51mm, 57mm, 60mm, 68mm, 2 swivel rods, 3 drills, 2 torsion bars, 1 Allen key.