A drill chuck has a chuck body having a plurality of angularly spaced and axially extending but angled guide grooves each holding a jaw that is axially displaceable between an axially front closed position and an axially rear open position. Each jaw has an outer edge formed with external teeth, and also has an axially rearwardly directed rear face extending at an acute angle to a plane perpendicular to the axis. A ring rotatable on the body about the axis has an internal screwthread meshing with the teeth, and an adjustment sleeve rotationally coupled to the ring is rotatable to move the jaws between the open and closed positions. A cover disk on the rear end of the body is formed with respective throughgoing chip-discharge holes each having an inner end aligned with a respective one of the grooves and an outwardly open outer end.