A core drill bit consists of a steel tube with diamond segments brazed or welded on the drilling end, and mounted on a rotating shaft. When in use the core bit is kept cool using water which also totally eliminates dust. Core drill machines can be operated in either vertical or horizontal direction. Core drilling techniques are used when precise, circular cuts are needed. Holes of almost any diameter are easily drilled to make openings for plumbing, electrical and HVAC installations. Core drilling is also commonly used to create for routing cables or placing anchoring bolts, installing load carrying devices or dowel bars, or for concrete sample analysis.

G.T. Diamond Drilling carries large diameter drill bits up to 800mm. Stitch Drilling is a method of drilling which can be used when the size or shape of the hole is abnormal. It is achieved by drilling a series of overlapping holes to create the required opening.