These cylindrical cups with serrated edge that we know them also as Hole Saws are for cutting various sizes of holes in a variety of materials. It is very important for Hole Saws to be durable and high-quality. Therefore, Ronix has manufactured the RH-5200 15Pcs HSS Bimetal Hole Saw Set, from a range of 19 to 64mm, to cover all different types of demands. 

• Constructed from high-quality Bi-Metal for rust proof, 2mm thick, much more durable and great heat resistance 
• Sharp teeth perfect for hole cutting on metal, wood, PVC board, plastic and drywall; clean and smooth cut; high precision. 
• Includes:  10pcs Hole Saw:
  3/4” (19mm),7/8"(22mm),1-1/8"29mm),
  1-3/8"(35mm),1-1/2"(38mm),
  1-3/4"(44mm),2"(51mm),2-1/8"(54mm),
  2-1/4” (57mm),2-1/2” (64mm)
  1 × Spare Pilot Drill for Replacement
  1 × Large Mandrel
  1 × Small Mandrel with Medium Adapter
  1 × Aluminum Case
  1 × Bonus Hex Key
• Different mandrels for saws of different sizes, compatible with most drills of other manufacturers; user's manual provides clear instructions and details about how to use safely 
• Everything in this kit is well organized in a solid Aluminum case, great for storage after using and easy carrying out for work; free of worry about losing small parts in the kit after handling