Features: Product Size:Drilling Diameter:21mm/0.83inch, Hex Shank Dia. 10mm, Drilling Depth 60mm, Overall Length 86mm. Positioning drill and blades are made of YG8, hardness ≥ 91HRA, bending strength up to 2200N/cm², resharpenable. The shaft rod is made of No. 45 steel, heat-resistant and corrosion resistant. After quenching, the hardness is extremely high, effectively avoiding bending of the shaft during use. 2mm super thick blade: Uses industrial grade YG8 blade, which extends the service life by 10 times compared to 1.3 mm thick blades. Woodwork hole saw is perfect for wood, plastic, plywood, solid wood board, plastic, furniture, door hinges, desk. Can not drill metal. The drilling process must be kept vertically and it is recommended to use a tool such as a vice to keep the material stable so that a smooth, precisely sized hole can be obtained. Adjust the slow drilling speed until the drill is fully positioned, and then gradually accelerate the speed. The speed is controlled at 2200~2500RPM for better effect. Specifications: Component:Stainless Steel Size:Approx.94x21mm/3.7x0.82inch Package Includes: 1Pc Woodwork Drill Bit note: 1.Please allow 1-2cm errors due to manual measurement, making sure that you not mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual of the item.