When the dead circle is large, the size can be changed by cutting gold and washer. The golden cutting method is to cut the dead ring into a section, and then weld, grind and polish it to reduce the size of the dead ring. The washer method is to make a washer with the same material as the ring and embed it on the inner wall of the dead ring to reduce the size of the ring.
The dead tail ring is small, and it is generally changed to a large size by adding gold. The method of adding gold is to cut the ring of the dead end ring into a section, and then add the metal of the same material to increase the size of the dead end ring by welding, polishing and electroplating.