Spline 1/2" x 36" with a 30" depth of cut. This ROTO-2 Carbide, high-performance bit allows for the best drilling, with less vibration in the quickest amount of time. Up to 50% more holes per bit. This Bit provides for Exact round holes. Exceeds ANSI Standards. The Best product on the market for All Concrete Drilling when using a spline drive rotory hammer!