Diamond core drill bits, also known as diamond corers, are suitable for drilling most common building materials such as aerated block, clay bricks, limestone, brick paving slabs, asphalt and concrete. When boring a hole with a diamond corer, the corer is mounted on an arbor. The arbor may have an SDS or a hex fitting appropriate to the drill or chuck used. In order to centre the corer a tapered drill bit is used to centre the boring hole and stop it wandering. It may be removed after the first few millimetres of cut if required.
A diamond corer consists of a metal cylinder, usually steel. A mixture of diamond crystals and bonding metal powders is hot pressed into segments. These segments are laser welded on to the cylinder to form a cutting head. The cutting head is slightly larger than the diameter of the rest of the corer to provide clearance during drilling and so that it does not get jammed in the hole. The sloping slots in the cylinder wall help carry the dust out. A diamond corer will cut clean accurate holes producing exact size holes with almost no break out. The core can be removed in one piece avoiding the need for making good by a brick layer or plasterer. Unlike traditional carbide tipped core drills diamond core drills require no hammer or percussion action when drilling.
