Because of the number of teeth and other operational benefits, Rotabroach Cutters do not require regrinding as frequently as twist drills. When sharpening, only .015" to .020" is commonly required if the tool was pulled at a reasonable wear point. If allowed to continue and the edge is badly worn, burned, or chipped, more material will need to be ground away.Rotabroach cutters do not have an infinite regrindability as do twist drills which can be ground back till virtually no flute exists. Hole integrity and depth is lost.
Rotabroach Cutters as well as twist drills have O.D. backtaper. As the end is reground, size is reduced. This becomes substantial when significant length is reground.Rotabroach Cutters have a limited regrind length. This length although limited, gives exceedingly long life, due to wear characteristics. By the time a Rotabroach Cutter has reached this length...it has paid for itself in increased production rates and quality of holes produced.