DEWALT® DW5764 4-Cutter Spline Shank Rotary Hammer Bit: This bit features a ROCK CARBIDE tip which maximizes carbide surface contact for longer bit life. The open head design channels dust into flutes for quicker drilling, along with a longer helix four flute design that expedites mill removal - also for quicker drilling. For use with all brands of spline rotary hammers. Commonly used for drilling anchor and through holes in poured concrete and other masonry up to 2" diameter. Diameter 1-1/2". usable Length 17: overall Length of 22".