When we cut the ring magnet (Fig. 1) into a sector magnet (Fig. 2), it can only be cut with a diamond grinding wheel because the workpiece is brittle. For this purpose, we have designed the clamp (Fig. 3). In use, the workpiece 4 is placed on the pressure seat 7, and then the pressure cover 3 is inserted into the pressure seat 7, and the workpiece 4 is pre-compressed by the spring L6, so that the pressure seat 7 is pressed. When rotating, the workpiece does not move relative to each other. Beam again