Abstract
We proposed a microprocessing method using a magnetic compound fluid for the inner surface of a tube made of a material that is difficult to cut, and clarified the processing characteristics and magnetic field distribution of the tool. The tool inserted into the tube comprises a stack of ring-shaped permanent magnets with spacers between them. There is an almost proportional relationship between the amount of material removed and the processing time, and the processed surface acquires a mirror finish. Moreover, for tools with shorter permanent magnets, the circularity is improved by processing.