A shim plate for milling tools for chip removing machining, including an upperside, an underside, and at least one side surface extending between the upperside and the underside and forming an angle ≦90° with the upperside. A through hole includes a first section mouthing in the upperside, and a second section mouthing in the underside and having a diameter that is smaller than a diameter of the first section. The upperside at least partially transforms into the side surface via an edge portion configured to be an active auxiliary chip-removing cutting edge upon failure of a cooperating cutting insert. The edge portion includes a chamfer surface that forms an obtuse angle (δ) with the upperside.