There are disclosed improved water-soluble metal working fluids comprising polyaspartic acid, amides and salts thereof, a corrosion inhibitor(s) and a basic additive said additive having sufficient basicity and buffering power to maintain the pH of the composition above about 8.5 and preferably above about 9. Such compositions are useful as lubricants in processes to cut, bend, grind and shape both ferrous and non-ferrous metals and tend to maintain higher pH values due to the incorporation of a basic additive. The polyaspartic acid and salts thereof are particularly advantageous in that the fluids can be easily disposed of after use without special treatment because polyaspartic acid and salts thereof are readily biodegradable.