Hi, I am just starting out on my jewellery career and I recently made

a Russian wedding ring (normally three different coloured gold bands

linked together) from which I read the instructions in a book. The

problem is that although I followed the sizing rules in the book, it

turned out no where near the size I had expected. Can someone please

let me know how I calculate the length of rod needed if for example

the ring circumference is 66mm what length do I have to cut the (half

round rod) if it is 3mm thick

Thanks in advance for your help