A cutting tool comprising: a cartridge having a cutting insert pocket; a cutter body having at least one cartridge pocket in which the cartridge is releasably retained; an adjustment screw having an axis of screw rotation and comprising an annular recess and a threaded portion; a protuberance protruding from the cartridge, the protuberance being snugly fitted in the annular recess thereby coupling the adjustment screw to the cartridge, the adjustment screw threadingly communicates with the cutter body, whereby screw rotation of the adjustment screw in opposite senses about the axis of screw rotation results in the bidirectional adjustment of the position of the cartridge in the direction of the axis of screw rotation; characterised in that the cartridge pocket comprises a base surface, a first side surface and a second side surface, the first and second side surfaces (28, 30) are oriented transversely to each other and to the base surface, a groove, bordered by the base surface and the second side surface, opens out to the cartridge pocket, wherein the adjustment screw is at least partially located in the groove; and the base surface is provided with a cartridge pocket through bore which communicates with a securing nut pocket, the cartridge has a cartridge through bore and is secured to the cartridge pocket by a cartridge bushing which is located in the cartridge through bore and threadingly received in a nut threaded bore of a securing nut located in the securing nut pocket; and in that a cutting insert may be retained in the cutting insert pocket and secured thereto by a securing screw which is located in a cutting insert through bore and threadingly received in the cartridge bushing. a cartridge having a cutting insert pocket; a cutter body having at least one cartridge pocket in which the cartridge is releasably retained; an adjustment screw having an axis of screw rotation and comprising an annular recess and a threaded portion; a protuberance protruding from the cartridge, the protuberance being snugly fitted in the annular recess thereby coupling the adjustment screw to the cartridge, the adjustment screw threadingly communicates with the cutter body, whereby screw rotation of the adjustment screw in opposite senses about the axis of screw rotation results in the bidirectional adjustment of the position of the cartridge in the direction of the axis of screw rotation; characterised in that the cartridge pocket comprises a base surface, a first side surface and a second side surface, the first and second side surfaces (28, 30) are oriented transversely to each other and to the base surface, a groove, bordered by the base surface and the second side surface, opens out to the cartridge pocket, wherein the adjustment screw is at least partially located in the groove; and the base surface is provided with a cartridge pocket through bore which communicates with a securing nut pocket, the cartridge has a cartridge through bore and is secured to the cartridge pocket by a cartridge bushing which is located in the cartridge through bore and threadingly received in a nut threaded bore of a securing nut located in the securing nut pocket; and in that a cutting insert may be retained in the cutting insert pocket and secured thereto by a securing screw which is located in a cutting insert through bore and threadingly received in the cartridge bushing.