When Machining with Internal Cooling
HSK holders Form A must be equipped with a coolant tube. If holders with internal cooling are used without coolant transfer units, this can damage the spindle.
For DIN 69893 Form C, -E and -F
no coolant tubes are required. The central coolant supply or sealing is effected by a clamping unit. The coolant tube is minimally movable after installation (according to DIN) (± 1 °).