1 PIECE TYPE CONTRUCTION CORE BIT Core bits are cutting tools used to remove a cylindrically shaped piece of material, called a core. Core bits have a hollow center, similar to hole saws, but differ in application. A hole saw is meant to create a large hole in a workpiece, while a core drill is designed to cut a hole and remove a core sample or to drill a hole without leaving material behind. Diamond core bits have diamond cutting tips and are frequently used for drilling in materials such as concrete, stone, and asphalt.