Quality wood drill bit set of 8pcs and hinged hard plastic storage case. Drill sizes include: 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, and 10mm. High carbon steel, hardness thermal treated. Wood drill bits specially designed head features two sides and two edges, precision positioning edge, cut and effort. Can be used in bench drill, electric dc / ac hand drill.