AR or Aspect Ratio is used in chain maille to describe the ratio between the Inner Diameter (ID) of a ring and the Wire Diameter (WD) that the ring is made in.
Why is this important and why do I need to know all this? Understanding AR will help you calculate easily the ring sizes you need for each weave. In chain maille one ring size does not fit all, and if you have the ideal AR of a weave, or the ability to calculate it, then you are well on your way to finding that perfect ring combination.
Each chain maille weave has an ideal AR and this information can be used to calculate what ID and WD you need to use.
The main formulas you would use are:
AR=ID/WD
WDxAR=ID
ID/AR=WD
Let’s see how AR is used in your everyday maille:
1.) You have done your first Byzantine Bracelet, using the pretty standard 18G (1.0mm) x 3.50mmID rings. These are the rings that your kit contained but now you want to move into other gauges….first you need to find out the AR(Aspect Ration) of the weave. To find out what the AR of this weave is we use the formula of AR=ID/WD …… AR=3.50/1.0 therefore AR=3.5.
2.) OK, so we have our AR worked out, and we have decided we want to do this weave in 16G(1.29mm). Taking the known information of AR (3.5) and WD(1.29) we can work out what the ring size should be…this is where the second formula comes into play WDxAR=ID……1.29×3.50=ID therefore 4.5. Your new ID would be 4.50mmID in 16G (1.29mm) wire. (Using inches …0.051″x3.50=0.1785 or 11/64″)
3.) You have the ring size and the AR needed but not sure on what WD it should be you would use the 3rd formula. You want to make box chain with 6.00mm rings. Box has an AR of 5 so your formula with this info is 6/5=1.2 or 16G wire.
The first two scenarios are the two main ones you will encounter when mailling, but it doesn’t hurt to understand them all.