1. Bi-metal hole saws: suitable for wood, composite building boards, plastics, synthetic resins, aluminum, cast iron below 10mm, and steel below 5mm. These materials are generally softer than 50 HRC, so bi-metal hole saws are recommended. M42 bi-metal has teeth that are not easy to break and offers high wear resistance, so bi-metal hole saws are recommended for these materials. 2. Pipe-specific hole saws: suitable for fire-fighting pipes, water pipes, shipbuilding, steel structure frames, cast iron above 10mm, and steel above 5mm. These materials are generally harder to drill than ordinary materials, so pipe-specific hole saws produced from imported saw blades, with hole depths up to 35mm or 48mm, are recommended for such materials. During use, pipe-specific hole saws have a significantly longer service life than ordinary bi-metal hole saws. 3. High-speed steel hole saws: suitable for sheets or round pipes under 5mm such as iron sheets, iron plates and stainless steel plates. High-speed steel offers good processability and a good combination of strength and toughness. Common high-speed steel hole saws are mainly made of grades 42, 43, 93 and 65. High-speed steel is also divided into solid and welded types; in general, solid high-speed steel is more stable in quality than welded high-speed steel. Since alloy hole saws tend to catch teeth when used with a pistol drill, high-speed steel hole saws are recommended when cutting round pipes. 4. Alloy hole saws: suitable for flat plates under 30mm such as iron sheets, iron plates and stainless steel plates.

Bi-metal hole saws are produced directly from heat-treated bi-metal saw bands. The high alloy steel body and high-speed steel teeth provide low vibration and faster sawing performance, with greater resistance to chipping and smoother cutting. 1. The bi-metal material extends the service life of the hole saw by 30%. 2. The addition of 8% cobalt makes the teeth harder, enabling cutting of a wide range of materials from wood, plasterboard, artificial marble boards, plastic products, non-ferrous metals, aluminum, steel plates and stainless steel plates. 3. The uniquely designed variable-tooth hole saw combines the fine cutting of a constant-pitch hole saw with the fast cutting and easy chip removal of a variable-pitch hole saw, providing dual functions. 4. Compared with other hole saws, it is less likely to pull teeth, lose teeth or produce long chips. 5. Cutting depth reaches 38mm. 6. Cutting diameter ranges from 14mm to 210mm. 7. Usage notes: when cutting wood, lift the power tool up and down to facilitate chip removal. When cutting metal materials, it is best to use cutting fluid to extend the service life of the hole saw.

A hole saw can cut very hard materials, including hardened steel, cast iron, brick and more, and is matched with a carbon steel arbor and a centering drill bit. The standard bi-metal hole saw can cut all workable metals including stainless steel, wood, nail-embedded wood, plastics, fiberglass, drywall, fiberboard and composite materials. The standard cutting depth is 1-1/2", and it can cut workpieces sized up to 2*4's. The bi-metal hole saw can cut all workable metals including stainless steel, wood, nail-embedded wood, plastics, fiberglass, drywall, fiberboard and composite materials. The standard cutting depth is 1-1/2", and it can cut workpieces sized up to 2*4's. The deep-cut bi-metal hole saw has the same range of application as the Master Cobalt® standard bi-metal hole saw, but with a greater cutting depth of up to 1-7/8".

Bi-metal material is a type of composite material, mainly produced through semi-solid metal forming technology. Recent industrialization focuses on bi-metal materials such as aluminum-steel, titanium-steel, copper-steel, aluminum-titanium and copper-aluminum. Because heterogeneous composite materials offer functional performance, lower cost and a wide range of applications, they enhance the development potential of traditional materials.