For the heavy-duty job of chopping out mortises by hand, the most effective tools are mortise chisels. They have a steeply angled tip and a thicker, more robust blade than a standard bench chisel. Mortise chisels are as much levers as they are chisels, designed to be driven deeply, then levered to remove waste. The thickness of the blades provides stiffness and helps prevent rotating in the cut, and the sturdy handles withstand heavy blows from a mallet without mushrooming.