【9-piece drill bit sets】5 mm, 6 mm, 6 mm, 8 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm * 160 mm; the drilling depth is 100 mm. This allows you to drill all common dowel holes. (For the safety of your machine and yourself, the use of a three-pronged impact drill is not recommended.) 【CARBIDE DRILL BIT】: The drill bit set is made of high-quality cemented carbide and is durable and rust-resistant. The tungsten carbide tipped drill head is harder, stronger, and more resistant to extreme loads; high-density drilling and fast waste removal. 【X-HEAD】: It features an innovative X-shaped geometry with a unique cross-spline design for optimal disassembly and ease of use. Fully hardened drill bit with double-fluted spiral for efficient debris removal. 【2-Hole Shank】Round handle, 2-hole drill bit, standard drill bits in individual red cases for concrete, granite, and stone. The rounded spiral geometry ensures optimal and more efficient dust and dirt removal. 【APPLICATION】: Suitable for drilling holes