Provided is a method of chamfer machining a silicon wafer which makes it possible to increase the number of machining operations that can be performed using a chamfering wheel used for helical chamfer machining in the case of obtaining a small finished wafer taper angle. The method in which helical chamfer machining is performed so that the finished wafer taper angle of an edge portion in the one silicon wafer is within an allowable angle range of a target wafer taper angle .sub.0 includes a first truing step; a first chamfer machining step; a step of determining a groove bottom diameter .sub.A of the fine grinding grindstone portion; a second truing step using a second truer taper angle .sub.2; and a second chamfer machining step. The second truer taper angle .sub.2 is made larger than the first truer taper angle .sub.1.

An application device is configured to clean grinding surfaces in a machine for grinding ophthalmic lenses, the application device including: a central portion having so as to mount the application device in the grinding machine; and a peripheral edge configured to receive an application surface to cooperate with the grinding surface of the grinding wheel so as to clean the grinding surface. It also relates to a cleaning kit including an application device and a cleaning solution, and to a method for cleaning grinding surfaces.

Disclosed herein is a cutting apparatus including a moving unit for moving a spindle to position a cutting blade, a rotary dressing mechanism for rotating a dressing grindstone on a rotational shaft parallel to the spindle, and an optical sensor for detecting the position of the outer periphery of the dressing grindstone. The cutting blade is positioned with respect to the rotary dressing mechanism depending on the position, detected by the optical sensor, of the outer periphery of the dressing grindstone, and the cutting blade is dressed by cutting into the dressing grindstone by a predetermined cutting distance.

In a method for pre-profiling a grinding tool, a device, in particular a gear grinding machine, for hard fine machining of workpieces and for pre-profiling grinding tools is provided, which includes a workpiece spindle for rotating a workpiece, a grinding spindle, which is feedable at least along an X-grinding-spindle-infeed-axis, for rotating a grinding tool, in particular a grinding worm or a grinding wheel, and a profiling device with a fixed first profiling plate. A grinding tool blank, in particular a grinding worm blank, is provided on the grinding spindle of the device. The device is brought into a profiling configuration. The grinding spindle is fed until the grinding tool blank is operatively connected to the first profiling plate. Finally, the grinding tool blank is pre-profiled.