The micromachining process for very small cutting depth of 1 mu m or less is not well understood in spite of the successful development of ultraprecision machining technology. Sliding along the clearance face of the tool due to elastic recovery of the workpiece and plowing due to the tool edge radius may become important in the micromachining range. To obtain a clear understanding of these two factors, an orthogonal cutting model, the round edge cutting model (RECM) was suggested.