Sometimes you need to know both the inner and outer diameters of a jump ring to pick the right one for your project, especially if you’re working on chain maille! The Fusion Team works hard to make sure the inner and outer diameters of our jump rings are listed on the Product Detail pages of our website. But if you don’t know both diameters of your jump rings, you can use today’s trick to figure it out!
You’ll need to know one of the diameters of your jump ring and the gauge of the wire to do this trick. You can refer to the handy chart below to figure out what the gauge of your jump ring converts to in millimeters. Once you have these two numbers you’re ready to use a quick math formula!
To find the inner diameter, subtract the gauge of your jump ring in millimeters from the outer diameter of the ring. This new number is the inner diameter! For example, if I have a 5mm jump ring that is made of 20 gauge wire, I would look at the chart below to find out that 20 gauge wire is 0.8mm thick and subtract that from 5mm. The inner diameter of my jump ring is 4.2mm!
To find the outer diameter, add the gauge of your jump ring in millimeters to the inner diameter of the ring. This new number is the outer diameter! For example, if I have a 4mm jump ring that is made of 18 gauge wire, I again check my chart to find out that 18 gauge wire is 1mm thick and then add that to 4mm. The outer diameter of my jump ring is 5mm!
|Approximate gauge to metric conversion:|
|12ga = 2.0mm||14ga = 1.6mm||16ga = 1.3mm||18ga = 1mm||20ga = 0.8mm|
|22ga = 0.6mm||24ga = 0.5mm||26ga = 0.4mm||28ga = 0.3mm||30ga = 0.25mm|
You can find more helpful hints for working with jump rings and making chain maille in our Q&A!
Happy Tuesday! – Gretchen