【SET OF 9 CONCRETE DRILL BITS】: 5mm. 6mm. 6mm.8mm. 8mm.10mm.12mm.14mm.16mm*160mm; The drilling depth is 100mm. It can drill all common bolt holes. (For your machine and personal safety, the use of a three-prong impact drill is not recommended.) 【X-SHAPED HEAD】 It features an X-shaped geometry with a cross-spline design for optimal disassembly and ease of use. Fully hardened drill with double spiral for efficient waste removal. 【2-HOLE SHANK】 Impact drill with round handle and two slots. Regular drilling tools for concrete, granite and stone. Provides optimal dust removal and dirt more efficiently thanks to the rounded spiral geometry. 【CARBIDE DRILL】 The drill bit set is made of high-quality carbide steel, durable and rust-proof. The drill head with tungsten carbide tip is harder and stronger and more resistant to extreme loads. 【APPLICATION】 Suitable for drilling holes in concrete, ceramic tiles, stone, wood, aluminum, plastic, concrete and multi-layer materials / For all drills with