This investigation has established the fact that the alloy 75-S can obtain maximum physical properties without being cooled to a temperature below the aging temperature at any point in the heat treating cycle. However, such a method of heat treatment in no way alters the time required for the precipitation heat treatment at 121 ℃. This refers to specimens of the type used in this investigation. The medium which is used for the constant temperature quench must be non-corrosive. Glycerine was used in this work because a supply of the material was in stock. / M.S.