upward curling chip. These chips generally form from intermediate cutting angles. Type II chips may form in ductile materials, such as metals. Type II chips may also form long, continuous swarf. Type III chip Type III chips form a compression failure of the material, ahead of a relatively obtuse cutting angle, approaching 90°. In some weak or non-ductile materials this may form an acceptable chip, usually as a fine dust, but often it gives rise instead to a random "snowplough" effect where the waste material is bunched up ahead of the tool but not cleared decisively away as a well-formed chip. This type of chip is formed by routers. It is also formed by woodworking scrapers, although when properly sharpened and used, these form such a thin Type III chip that it instead appears as a well-formed Type II chip. Their waste chip is thin enough that the compression failure volume is small enough to act as for the well-defined shear plane of the Type II. Type 0 chip This type was characterised later, by William McKenzie (1960). References Cutting tools Cutting processes Woodworking Metalworking