Routing hinge mortises for butt hinges is a huge time saver, but squaring off the round edges of the mortise can be fussy work. That's where this corner chisel can really clean up shop. One quick chop, and the corner chisel cuts a neat ninety degree corner that is perfectly aligned with the hinge gain. The corner chisel is razor sharp and spring-loaded, so it immediately returns to a ready position for the next hinge corner. Simple and effective! Features: Square edges of housing automatically align corner chisel with hinge mortise. Spring loaded chisel returns to ready position for quick, efficient chopping. Made from heavy-duty steel to withstand years of use.