Sizing an existing RWR (Russian Wedding Ring) is no different to
sizing a normal ring. Determine the size difference required and add
or remove the corresponding amount of metal from each ring.
The fact that each ring of the RWR is rather larger than the finger
size of the complete ring is irrelevant. It’s the difference between
the sizes that’s important.
Making a RWR from scratch is rather different.
For example, suppose the RWR is American size 5 and you want it to
be size 4.
The ID of a size 5 ring is 0.6141" and a size 4 is 0.5820". The
difference is 0.0321". Multiply this by PI (3.14159) to get 0.1008".
This is the amount of metal you have to cut out of each ring.
Regards, Gary Wooding