Socket mortise chisel with wood handle and metal ferrule to prevent handle splitting and mushrooming. Socket chisel is more expensive to manufacture compared to a tang chisel. Its advantage is the handle will not crack in use like a tang chisel . However should the socket wood shrinks and chisel loosens soaking handle in water will swell wood or use sticky tape to wedge socket tight to handle.
For maintenance sharpening use waterstone grit 1000 and above.