an apparatus for supplying a fluid to a passageway in a cutting tool includes a housing having a rotatable spindle thereon , the tool being releasably supported on the spindle for rotation therewith . a cooling medium supply ring rotatably supported on a shank portion of the tool has a first surface which faces substantially radially outwardly and slightly in the direction of rotation of the tool . a coupling head on the housing has a second surface thereon positioned for sealing engagement with the first surface when they are brought into angular alignment through rotation of the supply ring caused by frictional engagement of the supply ring and rotating tool . fluid passes from a passageway in the coupling head through aligned openings in the first and second surfaces , into passageways in the supply ring , and then through an opening in the shank portion of the tool and into the passageway therein .