Grain refining fluxes are used to introduce titanium and boron into molten metal. The use of these refiners yields a very fine grained metal structure, resulting in improved mechanical properties. The action of titanium and boron promotes the formation of numerous crystallization nuclei that inhibit grain growth, particularly during the heat treatment of castings. These products are recommended for all aluminum foundry alloys, including those used in sand, permanent mold, and low-pressure casting processes. Sodium-free formulations are also suitable for use with alloys containing more than 3% magnesium and with strontium-premodified alloys.