A core drill is a drill specifically designed to remove an annulus of material rather than an entire cylinder of the material being drilled, as a typical auger -type drill bit would. Core drills are used for many applications, either where the core needs to be preserved or where drilling can be done more rapidly since much less material needs to be removed than with a standard bit. This is the reason that diamond-tipped core drills are commonly used in construction to create holes for pipes, manholes, and other large-diameter penetrations in concrete or stone. Core drilling is performed when precise, circular diameter cuts are needed. Holes up to 60" in diameter can be drilled to virtually any depth. Core drilling is used for plumbing, electrical, and HVAC installations. Line drilling is an effective method for removing almost any thickness of concrete where other methods cannot be applied. Core holes are drilled in a series of overlapping holes, allowing for one large segment to be removed.