A process (invented about 1899 by Frederick W. Taylor and Maunsel B. White) for giving toughness to self-hardening steels. The steel is heated almost to fusion, cooled to a temperature of from 700¡ to 850¡ C. in molten lead, further cooled in oil, reheated to between 370¡ and 670¡ C., and cooled in air.