Tool spindles are cooled by water (with corrosion inhibitor), air or oil in order to protect the spindle components from overheating and to maintain temperature-dependent material characteristics.
The coolant is fed through the cooling coil, a wide milled "internal thread" in the housing around the motor spindle. The coolant heated by the waste heat from the spindle is cooled in suitable cooling units so that it can be fed back through the cooling coil again. In doing so, the correct composition of the coolant must be observed because the cooling coil could be destroyed or blocked through the effects of corrosion.
