Livingston Jewelers

Determining Ring Blank Lengths in millimeters

When designing a ring with a proper and snug fit, you must compensate for the thickness of the ring stock after measuring the ring size. Forcing the outside ends of the ring stock together for soldering compresses the inside circumference, making the ring smaller. As a general rule, the inner surface of the wire will compress, and the outer surface will stretch. The median line that runs down the center of the ring is what we want to plan for. This chart is designed to allow you to look up what you need and plan for your designs without having to take time to figure out the math yourself.

Use this table to determine the length of your Ring Blanks. The first table is a reference to American ring blank sizes in millimeters. So you may need to refer to the tables on the Determining Metal Gauges page first to convert from B. & S. Guage to metric. As a jeweler you should become comfortable with using metric measuments for all of your tasks at the jewelers bench.

Remember, when the metal is bent into a ring shape that the thickness of the metal will affect the length. That is why I am sharing this information. If you have a metal that is between two of the widths in this table, choose the column with the thicker metal and file the end a bit. This fall under the headding of "It is easier to remove a small bit of unwanted metal than to add it"

There are things that you need to consider as well when choosing the length of your ring blank. A wider ring will need to be made slightly larger to allow the clients finger to fit and prevent the ring being too tight. For a wider band, this allows for the muscles of the finger to flex and move without feeling bound and compressed.

The width of the average women's ring will typically be from 1.6 millimeters to 4 millimeters in width. You will also occasionally need to make a womans ring with an ultra-thin band that is less than 2 millimeters wide. Normally these fall into the 1.6 or 1.8 millimeter range and are wedding bands that complete a wedding set. You will occasionally need to make a womens ring that are wider than 4 millimeters. Most mens rings are wider from 4 to 7 millimeters. Rarely do you see mens rings go below 2 millimeter in width.

A good rule of thumb is that for every 4 millimeters in width, add a quater size to your ring stock when creating a custom ring. For a thicker band, a quarter size increase should be enough to compensate in your ring blank length. you can always tap it up very slightly because you have a lot of material to work with. For a band that is wide, but made with thinner materials, you might need to add a half size to your ring when you cut the stock.

This page does not take into account rings that have a "comfort fit" profile inside. A "comfort fit" ring will have a slightly domed profile inside the ring to alleviate the feeling of being too tight when you are moving your hand and finger. It is rare to make a custom ring that is a "comfort fit" and over 4 millimeters wide.

There are many websites, jewelers books and manuals and jewelry supply catalogs that will have a table like this. Pulled from many different sites, this should be accurate.
Formated so it follows accessibility requirements for the internet.

If you have suggestions for adding to this page, or comments, please email me at the link in the footer below.