Jump Ring Guide & AR Calculator
Calculate inner/outer diameter and aspect ratio for jump rings. Find which chain maille patterns your rings will work for.
| AR Range | Behaviour | Suitable Patterns |
|---|---|---|
| < 3.0 | Rigid, almost no movement | Solid ClosuresDecorative Links |
| 3.0 – 3.9 | Minimal flex, tight weaves | 2-in-2Box ChainByzantine |
| 4.0 – 4.9 | Moderate flex, versatile | ByzantineHelm ChainQueen Braid |
| 5.0 – 6.9 | Good flexibility, drapes well | European 4-in-1Japanese 12-in-2Half Persian |
| 7.0 – 9.9 | Very flexible, loose weave | Full PersianOrbitalShaggy Loops |
| 10+ | Extremely open, slinky | Flower ChainLoose Spirals |
| Pattern | Min AR | Max AR | Difficulty |
|---|---|---|---|
| Box Chain | 3.2 | 4.2 | Beginner |
| Byzantine | 3.5 | 4.5 | Intermediate |
| Helm / Parallel Chain | 4.0 | 5.5 | Beginner |
| European 4-in-1 | 5.0 | 7.0 | Beginner |
| European 6-in-1 | 5.5 | 7.5 | Beginner |
| Japanese 12-in-2 | 5.0 | 6.5 | Intermediate |
| Half Persian 3-in-1 | 5.0 | 7.0 | Intermediate |
| Full Persian | 7.0 | 10.0 | Advanced |
| Queen Braid | 4.2 | 5.5 | Advanced |
| Orbital | 7.0 | 10.5 | Intermediate |
| Shaggy Loops | 7.5 | 12.0 | Beginner |
| Mandrel (mm) | 16 AWG | 18 AWG | 20 AWG | 22 AWG | 24 AWG |
|---|
Understanding aspect ratio in chain maille
Aspect Ratio (AR) is the key number in chain maille. It describes how open a jump ring is relative to its wire thickness: AR = Inner Diameter / Wire Diameter. A ring with a 5mm inner diameter made from 1mm wire has an AR of 5.
Why AR matters: Each chain maille weave pattern has a "sweet spot" AR range. Too low and the rings cannot physically pass through each other or move; the weave locks up. Too high and the weave is too loose and floppy, losing its structure.
Inner vs Outer Diameter: The inner diameter (ID) is the mandrel size — the hole of the ring. The outer diameter (OD) adds two wire diameters to the ID. Always use ID for AR calculations, not OD.
Wire springback: When coiling wire around a mandrel, it springs back slightly when removed. Sterling silver springs back more than copper; harder wire springs back more than dead-soft. For precision, always test-coil a few rings and measure the actual ID before cutting a batch.