The invention relates to a water-miscible cooling lubricant concentrate which contains natural or synthetic mineral oils, emulsifiers, anti-corrosive agents, solubility promoters, preservatives, metal inhibitors and other standard additives and after dilution to an aqueous solution containing between 2 and 25 percent by weight has a pH between 7.0 and 7.5. As preservative and/or anti-corrosive agent said concentrate further contains a mixture of a) a reaction product of boric acid and a primary or tertiary alkanolamine and/or, b) an ethoxylated and/or propoxylated fatty acid or a fatty acid alkanolamide and at least one other compound selected from the group consisting of c) a carboxylic acid imide, a phosphoric acid ester, a triazole, a thiadiazole, an isothiazolinone, an imidazole, a guanidine, an aromatic carboxylic acid and 3-iod-2-propinyl-carbamate, and/or d) a methylol urea derivative.