Made from Tungsten steel and being hot-treated, the blade is characterized by high accuracy, cutting operation, good resistance to shock and good toughness. Small incision resistance, the opening speed, chip easy and no tremor. The perforation is , , no broken edge. Precision control: style reduces runout for more precise holes,Perfect for pocket holes, overlapping holes, and holes at the edge Forstner Drill Bit Package include 6PCS, 15mm/20mm/250mm/30mm/35mm/40mm, can meet your different needs. Wide range of applications - Any wood and wood , plastic, plywood and other materials you need to exquisite perforation Colour:Silver + Blue Material:Cemented carbide Size: 15mm/20mm/25mm/30mm/35mm/40mm Package Contents: 6 * Drill Bit Set Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.