The best method for entering precision circular cuts in concrete whether the plane is horizontal, vertical or overhead is Core Drilling. The hole’s diameters ranging from ½” up to 60” are cored in order to make openings for plumbing lines, electrical lines, sprinkler systems, HVAC ducts, fiber optics & conventional phone lines, computer lines & placing anchor bolts. Core drilling methods are widely used in underground utilities construction, most commonly, manhole taps, underground vault taps, & wherever sewer, water, steam, air or communication lines pass through a concrete or brick structure. Drilling depths are virtually unlimited with the use of barrel extensions.