Abstract: Injection mold for manufacturing disc-shaped plastic objects with a central hole, which mold comprises: a first mold part; a second mold part displaceable relative to this first mold part; which two mold parts are displaceable between a closed first position, in which they together partially bound a mold cavity corresponding to the shape of an object for manufacture, and an open second position in which a formed object can be removed; a third mold part which in an active position extends through the mold cavity and in the region of this mold cavity has a shape corresponding to the shape of the central hole, which third mold part is axially displaceable relative to the first and second mold parts between said active position and a retracted rest position; which third mold part bounds with the guide sleeve a channel which is connectable to the injection nozzle of an injection molding device, which channel can be opened and closed by means of a valve consisting of a valve seat which is formed by a part of the in