Eight ring (figure-8 eye) dimensions and size chart
An eight ring (figure-8 eye, 8の字環) is a small stainless wire part with a loop at each end. It is set into the body of a lure or jig, or used to join the line and the hook. Maker size tables use letters such as D, E and F; the diagram shows what each one measures.
| Letter | Meaning |
|---|---|
| Wire | Wire diameter; it matters most for strength. |
| D (D1, D2) | Inner diameter of a loop, sized for the split ring or line that goes through it. The two loops may differ. |
| E | Distance between the loop centers |
| F | Width of the waist. Where the two strands touch it is twice the wire. |
| A, B | Outer diameter of each loop (D + 2 × wire) |
| C | Overall length (E + (A + B) ÷ 2) |
Common sizes
Dimensions of 23 common market sizes, in mm. A, B, E and F are calculated from the wire, D1, D2 and the overall length C.
| Wire | D1 | D2 | A | B | E | F | Length C |
|---|---|---|---|---|---|---|---|
| 0.7 | 1.2 | 1.4 | 2.6 | 2.8 | 4.50 | 1.4 | 7.2 |
| 0.8 | 2.0 | 1.8 | 3.6 | 3.4 | 4.10 | 1.6 | 7.6 |
| 0.8 | 2.0 | 2.0 | 3.6 | 3.6 | 5.40 | 1.6 | 9.0 |
| 0.8 | 1.6 | 1.6 | 3.2 | 3.2 | 8.80 | 1.6 | 12.0 |
| 0.9 | 1.5 | 1.5 | 3.3 | 3.3 | 4.20 | 1.8 | 7.5 |
| 0.9 | 2.0 | 2.3 | 3.8 | 4.1 | 5.65 | 1.8 | 9.6 |
| 1.0 | 1.8 | 2.3 | 3.8 | 4.3 | 5.45 | 2.0 | 9.5 |
| 1.0 | 2.3 | 2.3 | 4.3 | 4.3 | 5.40 | 2.0 | 9.7 |
| 1.0 | 2.5 | 2.5 | 4.5 | 4.5 | 5.20 | 2.0 | 9.7 |
| 1.0 | 2.0 | 2.0 | 4.0 | 4.0 | 6.00 | 2.0 | 10.0 |
| 1.0 | 2.0 | 2.3 | 4.0 | 4.3 | 6.15 | 2.0 | 10.3 |
| 1.0 | 2.2 | 2.3 | 4.2 | 4.3 | 6.25 | 2.0 | 10.5 |
| 1.0 | 2.5 | 2.3 | 4.5 | 4.3 | 6.40 | 2.0 | 10.8 |
| 1.0 | 2.8 | 3.0 | 4.8 | 5.0 | 6.10 | 2.0 | 11.0 |
| 1.0 | 2.3 | 3.0 | 4.3 | 5.0 | 7.35 | 2.0 | 12.0 |
| 1.0 | 3.0 | 3.0 | 5.0 | 5.0 | 8.50 | 2.0 | 13.5 |
| 1.0 | 3.0 | 3.0 | 5.0 | 5.0 | 10.00 | 2.0 | 15.0 |
| 1.2 | 2.5 | 3.0 | 4.9 | 5.4 | 8.85 | 2.4 | 14.0 |
| 1.6 | 3.0 | 4.5 | 6.2 | 7.7 | 10.55 | 3.2 | 17.5 |
| 1.6 | 5.0 | 4.8 | 8.2 | 8.0 | 11.90 | 3.2 | 20.0 |
| 1.8 | 5.2 | 4.5 | 8.8 | 8.1 | 12.55 | 3.6 | 21.0 |
| 2.4 | 7.8 | 7.4 | 12.6 | 12.2 | 16.60 | 4.8 | 29.0 |
| 2.4 | 7.6 | 7.5 | 12.4 | 12.3 | 17.65 | 4.8 | 30.0 |
Makers use different dimensions for the same nominal size. Check the maker's table when you buy.
Choosing a size
- Wire: thicker for bigger fish and heavier lures. Thicker is stronger but heavier, and needs more room in the body.
- Loop inner diameter D: large enough for the split ring wire or the line to pass freely.
- Overall length C: set by how deep it goes into the body (around E) and how far the loop should stick out. A shallow set pulls out more easily.
Pick a preset or enter wire, D, E and F to get a 3D model of an eight ring, ready to drop into your lure design.