Cutting fluids for brittle materials, e.g., silicon ingot, comprise, in weight percent: A. 70-99% polyalkylene glycol (PAG), e.g., polyethylene glycol; B. 0.01-10% PAG-grafted polycarboxylate; and C. 0-30% water. These cutting fluids are used with abrasive materials, e.g., silicon carbide (SiC), to form cutting slurries. The slurry is sprayed on the cutting tool, e.g., a wire saw, to cut a brittle work piece, e.g., a silicon ingot.