cryogenic machining is a machining process where the traditional flood lubro-cooling liquid (an emulsion of oil into water) is replaced by a jet of either liquid nitrogen (ln2) or pre-compressed carbon dioxide (co2). cryogenic machining is useful in rough machining operations, in order to increase the tool life. it can also be useful to preserve the integrity and quality of the machined surfaces in finish machining operations. cryogenic machining tests have been performed by researchers since several decades, but the actual commercial applications are still limited to very few companies. both cryogenic machining by turning and milling are possible.