Abstract: This paper presents the experimental investigation of extra-fine metal-cutting for highphosphorus cast iron showing the determination of the reasonable rake angle & fhe reasonable relief angle of the cutting tool, the influences of the thickness of cut, the cutting speed & the radius of the tool-tip on the cutting temperature & the surface finish of the workpiece It is pointed out that the selection of a reasonable a/P ratio is important during exfra fine metal-cutting for cast iron.