A must for creating a 90° square corner required for hanging windows and doors, installing locks, etc, this spring loaded corner chisel is more efficient than a hand chisel, and works quickly to ensure that corners are perfectly square. Compact enough to carry in your pocket, with a 3/8-inch cutter edge, this handy tool creates a 90 degree square corner when simply placed on any corner and tapped with a hammer. With Big Horn’s Corner Chisel self-aligns, accuracy is never an issue; you get the right fit every time with minimal maneuvering. This corner chisel is the answer to clean, quick, and accurate mortising. HSS blade give you an edge when forced into a corner..