Despite careful measurements, the finished ring may be too tight or too wide. It can then be changed. To this end, the professional will use two methods: It will either be stretched, or, in case of a major difference, the ring will be opened, and additional material will be added. In the case of making the ring tighter, it can be worked with a machine. It is also possible to remove a piece of the material.
Whether the procedures are applicable to your ring depends on whether and how well the ring was filled with stones and the material from which it was made. Gold and platinum are usually easy to change, but stainless steel represents a greater challenge. Gemstones or diamonds can lose their hold with the changes made, which is why they may have to be re-inserted. Engravings sometimes have to be completely recreated.