Coolant is so critical to the deep hole drilling process that today’s most advanced deep hole drilling systems control it in the same way as a machine spindle or shaft. Careful management of coolant pressure, filtration, temperature, and flow is the key to optimizing the deep-hole drilling process. This requires the integration of programmable, infinitely variable flow-based control capabilities into the deep-hole drilling machine itself. The result is a system with the necessary adjustability to ensure that the pressure in the cooling system never exceeds that required for efficient chip evacuation and precise drilling.

For many years, the most advanced coolant delivery system, other than the overflow type, was the through-spindle/through-tool coolant system. Then, the advent of high-pressure cooling systems with operating pressures around 1,000 psi changed the cooling technology landscape, with exceptionally effective tool cooling and efficient chip evacuation for most traditional machining operations. Drilling applications, primarily those using twist drills, are the main driver for the development of high-pressure cooling systems, especially deep-hole drilling applications where depth-to-diameter ratios are typically 10:1 or higher.