$99. The Countersink will cut a funnel shape from the 2 9/16 Inch mortise hole. This allows the tapered end of the tenon log to fit flush inside the mortise hole log. Using tapered countersinks give the joint a ‘flush’ look and are a matter of preference. It does not necessarily make the joint stronger. Made from high tensel steel. Fits a 1/2 inch or larger drill.