Core Drill

Core drill is a drill specifically designed to remove a cylinder of material, much like a hole saw. The material left inside the drill bit is referred to as the core.
Core drills used in metal are called annular cutters and used for concrete and hard rock generally use industrial diamond grit as the abrasive material and may be electrical, pneumatic or hydraulic powered. Core drills are commonly water cooled, and the water also carries away the fine waste as a slurry.