Ring size

Jewelry Discussion
1

Hi Jeff

The size N in your US size is between 6 1/2 and 7 inside
diameter is .6765 inch or 17.183 m/m. if you take the inside
diameter and add the thickness of metal of the shank and then
multiply by 3.14 it will give you the length of the shank
required.

Hope this helps

Best wishes

Major

2

Interesting. I haven’t come across this system before. Would
you give us a tabulation comparing the numeric and alphabetic
sizes ? Thanks. sol K.