A 3/4\" hollow square mortice chisel with bit from Draper The Draper 48080 3/4\" hollow square mortice chisel with bit is manufactured from high carbon steel hardened and tempered. The chisels are finely ground and polished with honed cutting edges. Chisel shank diameter 13/16\"  Features: Expert Quality, manufactured from high carbon steel hardened and tempered  Chisels are finely ground and polished with honed cutting edges  Chisel shank diameter 13/16\"  Specification: Chisel Bit Diameter: 1/2\" Chisel Shank Diameter: 1.3/16\" Mortice Depth: 4.11/16\" Mortice Square: 3/4\"