A core drill uses a hollow drill bit to cut into concrete, stone and other kinds of aggregate. The core is what comes out of the drill in cylinder form. The hole that is left behind is used to start new construction projects or other renovations. The surrounding area is left intact so there is no disruption which needs repairing once the drilling is complete.
Drills are powered by hydraulics, pneumatic systems or by electricity. The drills themselves are often made of diamond crystals and the cutting surfaces on the bits are made of carbide. Carbide may overheat so, to prevent this, a water cooling process keeps the bit cool while keeping dust from spraying outward when concrete is being cut.