The experimental observations of the four cutter blade specimens were expressed in terms of linear wear rates(mm h -1) as shown in Figs, 2-5. At the initial stages, the wear rates increase with time abruptly. With the increase of cutting duration, the wear rate decreases gradually as the rake angle/cutter blade edge thickness increases. However the data scattered significantly at the prolonged stage of wear testing, which is different from the general wear process that consists of three stages(cutting tools), and data scattering occurs mainly in the initial wear stage. The meshing(contact) of the fixed and stationary cutter blades caused the high wear rate in the initial stage. Another main factor that contributes to the rapid wear is the geometry of the cutting edge. In the beginning, the cutting edge is thin and sharp. The radius of the initial cutting(sharp) edge is relatively small(approximately 0.06 mm). Such a geometry reduces the resistance to surface fatigue wear and results in the fluctuation of wear. This implies that there exists more than one type of wear mechanism which occur randomly at different time frames and different wear locations. In the steady wear stage(stage II) the wear rate keeps increasing linearly. It is noted that for the thin edge cutting blade, a third rapid wear stage was not found. The wear rate was basically unchanged until failure. This could be explained from the cutter blade wear research of the second where the cross-sections of the cutting edge become wider(i.e., the curvature of cutter blade become larger). From this observa- tion, apart from the working environment factors, the geo- metry of the cutting blade is the most significant factor that contributes to the difference in wear characteristics between thin blades and common machine tools. treated as a surface damage phenomena, Wear is always therefore study of the damaged surface contour is one of the best ways of analysis. An SEM photograph of an untested cutting blade is shown in Fig. 6. Fig. 7 indicates that abrasive particle wear is one of the factors that contributed to the wear of the blade. However, such kind of wear is insignificant for this type of cutting because there is no sliding action occurring. The most significant factor that contributes to the wear is plastic deformation, which produces scratches, lip-shape projec tions and depressions(Fig. 8). As the plastic deformation cycle repeats for many times, work-hardening together with fatigue-induced crack occur. Fig. 9 shows the surface appearance of a worn-out debris particle just before it was detached from the blade. The debris surface is full of plastic deformation lines