A power resistor comprises a tubular housing composed of metal and a resistor element received therein, wherein the housing has four side walls that extend along a longitudinal axis of the housing between two ends and define a rectangular cross-section. The housing comprises four edges of the four side walls at at least one of the two ends. Two of the four side walls have a respective incision at their edges for introducing a fastening element and the two other side walls have a respective clearance in alignment with the oppositely disposed incision to facilitate a placement of a tool at a fastening element introduced into the respective incision.