Residues resulting from the distillation of fatty acids obtained from fat-splitting processes are converted by the process of this invention to useful metal working lubricants. The present process utilizes distillation residues, which are typically viscous oils ranging in color from dark brown to black and which heretofore had little or no commercial value and were burned or otherwise disposed of, to produce lubricants having performance characteristics which make them suitable for use in continuous metal-casting and other metal working operations.