The illustrated optimum, good and minimum required coolant volume apply only to spiral-fluted Series drills 60.68. In contrast to the pressure, which is a feature of the machine tool; the cooling system fitted to it and also the possibility of leakage, volume does not depend on the machine (fig. 1). The pressure figures given are therefore recommendations which serve only as guidelines.

The diagrams shown are for drills in their most important application, machining of steel. But they are also guidelines for the machining of other materials, primarily because the highest coolant pressures are constantly required for the machining of steel.

Coolant pressures and volumes - 60.68 bits

fig.1: Required coolant pressures and volumes for drills with internal spiral coolant ducts.