An alkali metal sulfonate mixture for metalworking applications, a method for making the sulfonate mixture, and compositions containing the sulfonate mixture. The mixture includes a reaction product of a first synthetic mono-hydrocarbyl substituted sulfonic acid having from about 20 to about 50 carbon atoms in the hydrocarbyl substituent, a second synthetic mono-hydrocarbyl substituted sulfonic acid having from about 10 to about 16 carbon atoms in the hydrocarbyl substituent, and an inorganic alkali metal base. The reaction product has a number average molecular weight ranging from about 400 to about 500 and a substantially bimodal molecular weight distribution.