Coolant supply is required to cool the spindle and protect against overheating. Also, during the milling process, coolant can be supplied to the processing zone to increase tool life, improve the quality of the machined surface and remove (wash) chips. CNC machines are equipped with an automatic coolant system. This system is controlled by several M codes.
М07 – turning on the coolant supply.
М08 – inclusion of an additional supply of coolant.
М09 – coolant shutdown. The M09 command turns off the coolant and cancels the M07 and M08 commands.
M13 - Enable cooling and spindle rotation clockwise.
M14 - Enable cooling and spindle rotation counter-clockwise.