Features: Made from strong HSS(high-speed-steel), durable and firm Ideal for cutting hard materials like wood, plastics, laminates and aluminium, etc. Suitable for use in carpentry and crafts Material: HSS Color: Sliver Maximum RPM: 20,000 Size: Hole Diameter: 6.35mm Mandrel Diameter: 3.17mm Blade Diameter: 22mm, 25mm, 32mm, 35mm, 44mm, 50mm