A cutting tool has a cutter body, which carries a cutting insert, and an adapter, which has a longitudinal adapter axis, wherein a locking screw attaches the cutter body to the adapter. A coolant volume is defined in a vicinity of a meeting of the cutter body, the adapter and the locking screw. The adapter contains an axial adapter bore. The locking screw contains a transverse locking screw bore in fluid communication with the axial adapter bore. The locking screw further contains a peripheral transverse locking screw bore passage in fluid communication with the coolant volume and the transverse locking screw bore. The coolant volume and the transverse locking screw bore are in fluid communication with the cutter body coolant passage.