Use of a blade holder comprising a blade seat comprising a holder connection surface and longitudinal jaws disposed on opposing sides of the holder connection surface , and a holder passageway configured for conveyance of coolant and comprising a coolant path extending therethrough from a holder inlet aperture to a holder outlet aperture formed at the holder connection surface , wherein the holder connection surface is formed with a sealing element recess that surrounds the holder outlet aperture ; a sealing element is mounted in the sealing element recess ; wherein the holder passageway comprises a preceding portion and a deceleration chamber closer than the preceding portion to the holder outlet aperture , and a transition region at which the preceding portion transforms into the deceleration chamber ; in the preceding portion at the transition region , the holder passageway has a preceding portion cross-sectional area (A P ) extending perpendicular to the coolant path, wherein: in the deceleration chamber at the transition region , the holder passageway has a deceleration chamber cross-sectional area (A D1 ) extending perpendicular to the coolant path, and the deceleration chamber comprises a barrier surface facing the coolant path of the preceding portion at the transition region ; characterized in that the use includes conveyance of coolant to the holder inlet aperture at a pressure in excess of 12 megapascal (120 bar). a blade seat comprising a holder connection surface and longitudinal jaws disposed on opposing sides of the holder connection surface , and a holder passageway configured for conveyance of coolant and comprising a coolant path extending therethrough from a holder inlet aperture to a holder outlet aperture formed at the holder connection surface , wherein the holder connection surface is formed with a sealing element recess that surrounds the holder outlet aperture ; a sealing element is mounted in the sealing element recess ; wherein the holder passageway comprises a preceding portion and a deceleration chamber closer than the preceding portion to the holder outlet aperture , and a transition region at which the preceding portion transforms into the deceleration chamber ; in the preceding portion at the transition region , the holder passageway has a preceding portion cross-sectional area (A P ) extending perpendicular to the coolant path, wherein: in the deceleration chamber at the transition region , the holder passageway has a deceleration chamber cross-sectional area (A D1 ) extending perpendicular to the coolant path, and the deceleration chamber comprises a barrier surface facing the coolant path of the preceding portion at the transition region ; characterized in that the use includes conveyance of coolant to the holder inlet aperture at a pressure in excess of 12 megapascal (120 bar). in the deceleration chamber at the transition region , the holder passageway has a deceleration chamber cross-sectional area (A D1 ) extending perpendicular to the coolant path, and the deceleration chamber comprises a barrier surface facing the coolant path of the preceding portion at the transition region ; characterized in that the use includes conveyance of coolant to the holder inlet aperture at a pressure in excess of 12 megapascal (120 bar). <EOS>