Core drill, bright HSS with 19 mm Weldon shank and 2 driving surfaces. Inner bore is 6.35 mm. The core drill only cuts a thin ring of material. Ejection of the remaining drill core is facilitated via guide and ejector pin by spring force. Quick removal of the chips upwards minimizes the risk of breakage. It requires relatively little energy, even for large drill diameters, and comes with a pre-cutter and after-cutter.