A grounding brush assembly includes a grounding brush having a plurality of conductive fibers and a support including a mounting portion housing the conductive fibers and first and second lateral flanges extending from the mounting portion and fitting axially around the conductive fibers. A mounting plate is integral with the support and is provided with at least one radial portion extending radially outwardly relative to the mounting portion of the support. The free end of the radial portion of the mounting plate at least partially defines the outer diameter of the assembly.