A device for axially preloading a machine element that is arranged in a housing, with an annular steel spring that has an open hollow profile in cross-section, on which at least on one side is molded an annular collar that rests on the machine element and that has an axial contact surface, the steel spring being preloaded via a safety element against the machine element with a force that exceeds the operating force that occurs. A structurally simple device that ensures high preloading forces with advantageous tolerance compensation is achieved by the steel spring with an axisymmetrical, semi-circular section with an essentially uniform radius R1 undergoing transition indirectly or directly via a smaller radius R2 into the annular collar.