How to Choose a Hole Saw for Different Materials
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.