Abstract: An apparatus for securing one or more diamond segments to a core bit of a diamond core drill includes a coupling ring to which one or more diamond segments are secured. An opposite end of the coupling ring is welded to a core bit. The coupling ring may be steel and may include a tapered portion or groove adjacent to an end of the core bit. An outer diameter formed by the diamond segments may be greater than an outer diameter of the core bit to reduce wear and an inner diameter formed by the diamond segments may be smaller than an inner diameter of the core bit to prevent a core of workpiece material from lodging in the core bit.