SUPER MATERIAL HSS high speed steel hole saw, which has high hardness and wear resistance. After high-density grinding and high-end heat treatment, it has high strength and precision to do the cutting smoothly. 5 HOLE SAW SET 16mm/0.6 inch, 18.5mm/0.7 inch, 20mm/0.8 inch, 25mm/1 inch, 30mm/1.2 inch; Length: 65mm / 2.55inch, Diameter: 8mm8; 5 pieces Hole cutters are individually packed in a plastic box, all come with their own Allen key to remove the pilot bit and the bit also unscrews from the shank. HIGH EFFICIENCY: Cuts quickly, with sharp blades and high hardness, in just a few minutes, the HSS hole saw kit cuts holes precisely in laminates of steel, stainless steel, iron, copper, brass , aluminum, fiberglass, formica, etc. INTELLIGENT DESIGNThe hole cutters use a spring-loaded design which is perfect for chip removal, drilling efficiency is superior.The important thing is that the handle adopts the hexagonal design, which makes the drill more stable, could totally avoid the slipping problem when we use it. WIDE APPLICATIONHole saws are designed for thinner steel drill bits. They can be perfectly installed on locks, knobs on doors and cabinets or larger diameter holes. It is also suitable for bench drills, electromagnetic drills, pistol drills and impact drills. It is also suitable for stainless steel plates, square tubes, iron, cast iron, wood etc. High speed HSS hole saw - your assistant in high efficiency life. Premium materials. High speed steel hole saw through special heat treatment, sharp edge, high strength. High strength, high precision. Its safe and premium material you don't need to worry about product quality or health issues. Features: Material: HSS6542. Hardness: HRC 65. Surface treatment: titanium coating. Type: hole saw. Hole saw diameter: 16 mm , 18.5mm, 20mm, 25mm, 30mm. Shank diameter: 8mm. Hole saw blade length: 65mm. Package weight: 308g. Application: Widely used in bench drills and electric drill chucks for machine tools, etc. Warning and precautions : 1. Use oil or water to lower the temperature before drilling hard materials (such as steel, stainless steel, etc.). Otherwise, the bit may be broken at high temperature. 2. Wear goggles to protect your eyes, please wear a protective mask when working uphill. 3. Please wear the earplugs when you need to work for a long time, to reduce the noise impact. 4. Remove anti-rust oil after use for longer life. 5. Please choose lower speed when continuous cutting. 6. Please do not allow the edge of the hole saw to make a violent or strong impact when cutting, so as to prevent the blades from being broken. 7. Please use coolant when working on hard materials. 8. There may be a slight difference in weight and