General description Professional Quality Cobalt Metal Drill Bit Set featuring a set of 5 hole saws designed for drilling through hard materials such as steel, aluminum, and plastic. This set includes drill bits with diameters of 16 mm, 18.5 mm, 20 mm, 25 mm, and 30 mm, ensuring versatility for various applications. Technical specifications Material: HSS Cobalt (5% cobalt) Working length: 1.5 cm Diameter options: 16 mm, 18.5 mm, 20 mm, 25 mm, 30 mm Installation Position the center drill bit accurately on the workpiece. Start drilling slowly at a low speed. Ensure the drill is held perpendicular to the workpiece. Use cutting oil for improved performance. Usage These hole saws are ideal for creating holes in various materials, including: Stainless steel Alloy steel Metal Plasterboard (placo) Plastic