With the society developing there are many applications for ferrous metals components with the optical quality surface finish and dimension accuracy associated with single point diamond turning. Ferrous metals, as many other materials, are not normally considered turnable with diamond because the diamond wear rate is too high and surface roughness too low on ferrous metals to make the process attractive.The paper researches on the influence of cutting data on work piece surface roughness and wear of cutting tool when natural diamond cutting ferrous metals. The paper presents a set of ultrasonic vibration cutting instrument such as a set of piezoelectric ceramic actuator with high stiffness, the ultrasonic generator, the ultrasonic transducer, the ultrasonic amplitude transformer and other necessary parts. The experiments are doing on the precision lathe, S1-222, and the measured data are analyzed. Experimental results show that vibration cutting has much advantage over the conventional machining. It is shown from the experiments that the ultrasonic vibration cutting process, which possesses some exclusively meritorious features, such as lower cutting forces, higher accuracy and.fine surface of the work piece.It puts forward to a new method of using natural diamond ultrasonic vibration to cut ferrous metals parts on the condition of carbon-saturation. The result shows that surface roughness and abrasion on tools and indicates the result that in a carbon-rich atmosphere and presents successful experimental results: it can get better surface roughness and lest abrasion on tools than the cutting situation that only assisted by ultrasonic vibration.