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A modified Ausform process has been developed which improves the fatigue properties of spring steels. In brief, the process combines metal deformation with heat treatment. The fatigue resistance of SAE 5150 and 1052 steels is greatly improved by this treatment. The amount of deformation directly influences the fatigue resistance; and with more than 50% deformation, the fatigue life is improved by 700% over that of SAE 5160 spring steel. For a 100,000 cycle minimum life, both maximum stress and stress range can be increased by 30,000 psi over that of conventionally heat treated SAE 5160 steel. Superior fatigue properties have been obtained in sections with thicknesses of 0.200-0.500 in. Surface treatments such as sandblasting, shot peening, and glass bead peening are effective in prolonging fatigue life; glass bead peening was by far the most effective. Modified Ausformed steels display an unusual fracture behavior which is beneficial in fatigue and notch toughness.