The present invention refers to a removable cover plate (1) to be used in the threshing modules (D) of the agricultural machines (A), specially the grains harvesters, being formed by technical and functional features capable of providing a uniform and homogeneous distribution of the grains onto the cleaning and harvesting system of the machines. More preferably, the removable cover plate (1) of the present invention is designed to be applied to at least one part of a concave (10) of a threshing module (D) of a grains harvester (A), being said threshing module (D) endowed with at least one rotor (R) and a least one concave (10) mounted around the rotor (R), to which it is attached and installed a removable structure (2) that has a material retention surface (3), in which are provided openings (4) to limit the grains and/or MOG (M) passage.
