The copying characteristic of the tool motion on the workpiece profiles is investigated. Assuming that the workpiece profile consists of sinusoidal-wave components, the amplitude ratio between the workpiece profile and the tool motion is defined as copying rate C(r). An experiment was conducted to identify C(r) in shaping of electroless plated nickel. With polycrystalline diamond tools, the copying rate was obtained as C(r) =1.16. The result indicates that the amplitude of the workpiece profile can be larger than that of the tool motion. Shaping of slot profiles was carried out to investigate the influences of depth of cut, rake angle and relief angle on the copying characteristic. The depth of slot was larger than the tool displacement in the Z-direction by 0.1-0.4 mu m when the rake angle was -5 degrees and the relief angle was 12 degrees.