In general terms, the magnetorheological finishing (MRF)1 process occurs as follows (refer to Fig.1). A workpiece is installed at some fixed distance from a moving wall, so that the workpiece surface and the wall form a converging gap. An electromagnet, placed below the moving wall, generates a non-uniform magnetic field in the vicinity of the gap. The magnetic field gradient is normal to the wall. The MR polishing fluid is delivered to the wall just above the electromagnet pole pieces. The MR polishing fluid is pressed against the wall by the magnetic field gradient, acquires the wall velocity, and becomes a plastic Bingham medium before it enters the gap. Thereafter, a shear flow of plastic MR suspension occurs through the gap, resulting in the development of high stresses in the interface zone and thus, material removal over a portion of the workpiece surface. This area is designated as the “polishing spot” or removal function.