Spring Back
The official definition of spring back:
"Spring back" is the geometric change made to a part at the end of the forming process when the part has been released from the forces of the forming tool.
Spring back in our case comes from the metal wire being wound around a round mandrill. The wire wants to try and return to its original shape of being a wire.
When we put this under a large amount of tension, some of this tension gets released when we cut the wire free of the spool\mandrill.
This is what we refer to when we use the term spring back.
As an example, when your coiling 16g wire against a 5/16 mandrill, and you release the coil, the ID of the coil ends up slightly larger. Say 21/64 or 11/32.
Some materials, and some sizes have more spring back than others. A lot of the time its the smaller gauges against a larger mandrill. For example, and 18g wire against say something larger than 5/16.
This is why we calculate AR, and show you the math on each one of our products. Sometimes this will make a difference in your weaves.
Some specific chainmaille weaves are very aspect ration (AR) sensitive and require that you have them very close to bang on.
When working with chain maille jewlery the aspect ratio is not always a factor, such as an earring.
Not all jump rings are created the same, or wound the same direction. Also note that colored jump rings, or anodized as they are called also have a different aspect ration from a bright aluminum jump ring. This is due to the anodizing process.
With that said, they are going to be very very close.