The Robert Sorby sash mortice chisels have a trapezoidal profile to the blade, this shape prevents them from binding in the cut. A trapezoidal chisel has a wider bottom blade with than the width of the spine. The angle for this chisel is 2¡.
These are a heavy duty chisel and are desgined to stand up to levering out waste from door locks, tenons and hinges.
They are fitted with a traditional boxwood handle.