Patent ID: 8567872

Claim:
An apparatus for grinding material, comprising: a grinder bit suitable for a power hand tool comprising: a drum; a plurality of grinders for grinding material, at least a portion of the grinders affixed longitudinally in a first helical pattern along the outer surface of the drum; and a plurality of cleats for removing the material ground by the grinders, at least a portion of the cleats at least partially box shaped and affixed longitudinally in a second helical pattern along the outer surface of the drum, at least a portion of the grinders along the first helical pattern is interdisposed with at least a portion of the cleats along the second helical pattern, wherein at least one cleat has a first surface and a second surface non-continuous from the first surface, at least a portion of the second surface substantially parallel to the first surface and opposed to the first surface, wherein the first surface and the second surface are interchangeable such that in a first state the first surface forms a leading portion of the at least one cleat and in a second state the second surface forms a leading portion of the at least one cleat.