The number of flute has an impact on the machine's feed speed, the surface finish of the product, and the chip cutting ability of the tool. Fewer flutes are best for chip evacuation, while more flutes produce a smoother surface finish. If the number of flutes increases, the feed rate must be increased or the spindle speed must be reduced to maintain a constant chip load. Therefore, it remains to select an end mill with fewer or more flutes depending on the speed capabilities of the CNC machine and spindle.