<p>A milling cutter (3) is mounted on the spindle (2) of a milling machine (1) by means of a key which prevents rotation but permits axial movement. A compression spring (14) presses the cutter (3) against a ball thrust bearing (7) fitted in a housing (6). The housing (6) is restrained by a ball (11) and screw (10) which is screwed into a support (5) rigidly attached to the milling machine. By rotating the handwheel attached to the screw (10) the axial position of the milling cutter (3) can be very accurately adjusted and then locked by means of the nut(12).</p>
