Some coatings, such as TiAlN, enable dry machining when drill ductile cast iron, but coolant is desirable to help evacuate the material's small, curled chips. Flood coolant can be appropriate for holes less than 1.5 to 2 diameters deep, according to Bob Jennings, product manager for Ingersoll Cutting Tools, Rockford, Ill. Jennings noted that the toolmaker offers standard Qwik-Twist replaceable-point drills to drill up to 8 diameters deep.