1Made of premium M42 high speed steel, sturdy and durable 2The blade is extremely sharped, with good perforation capability. 3Taking the form of a short open cylinder with saw-teeth on the open edge, perfect for installing locks, knobs in doors and cabinets 4Can be used to make holes in wood, thin steel sheet, aluminum alloy and other soft metal sheet. 5The newly designed chip removal groove, it can discharge the chip rapidly, and will not cause the crack and stuck piece phenomenon Features: Made of premium M42 high speed steel, sturdy and durable The blade is extremely sharped, with good perforation capability. Taking the form of a short open cylinder with saw-teeth on the open edge, perfect for installing locks, knobs in doors and cabinets Can be used to make holes in wood, thin steel sheet, aluminum alloy and other soft metalsheet. The newly designed chip removal groove, it can discharge the chip rapidly, and will not cause the crack and stuck piece phenomenon Specification: Material: M42 High Speed Steel Hole diameter: 16mm/0.6in, 18mm/0.7in, 20mm/0.8in, 22mm/0.9in, 25mm/1 0in,30mm/1.2in, 32mm/1.3in, 35mm/1.4in, 40mm/1.6in, 50mm/2.0in, 53mm/2.1in Uses: Opening hole Weight: Approx.1073g/37.8oz Package list: 11 x Hole Saw drill bit