My jump rings are made completely by me - hand coiled wire on hardened steel mandrels, then precision cut for perfectly flush cut rings. Tumbled with stainless steel shot to clean, harden and bring them to a beautiful shine makes them perfect for making chainmaille or to use however you like in your own handmade jewelry.
20g wire diameter: 0.812mm
wire gauge | approx. inner diameter (mandrel size in mm) |
approx. | aspect ratio | ring count per ounce troy | ||||||
---|---|---|---|---|---|---|---|---|---|---|
1 ozt | .75 ozt | .5 ozt | .25 ozt | .125 ozt | .0625 ozt | |||||
20g | 2 | 3.7 | 2.5 | 748 | 561 | 374 | 187 | 93 | 47 | |
2.25 | 3.9 | 2.8 | 687 | 515 | 343 | 171 | 85 | 43 | ||
2.5 | 4.2 | 3.1 | 635 | 476 | 317 | 158 | 79 | 40 | ||
2.75 | 4.4 | 3.4 | 616 | 462 | 308 | 154 | 77 | 38 | ||
3 | 4.7 | 3.7 | 552 | 414 | 276 | 138 | 69 | 34 | ||
3.25 | 4.9 | 4.0 | 518 | 388 | 259 | 129 | 64 | 32 | ||
3.5 | 5.2 | 4.3 | 488 | 366 | 244 | 122 | 61 | 30 | ||
4 | 5.7 | 4.9 | 437 | 328 | 218 | 109 | 54 | 27 | ||
4.5 | 6.2 | 5.5 | 396 | 297 | 198 | 99 | 49 | 24 | ||
5.0 | 6.7 | 6.2 | 362 | 271 | 181 | 90 | 45 | 22 | ||
5.5 | 7.2 | 6.8 | 333 | 250 | 166 | 83 | 41 | 21 | ||
6.0 | 7.7 | 7.4 | 308 | 231 | 154 | 77 | 38 | 18 | ||
mandrel diameter | actual ID* |
actual OD* |
actual AR* |
|||||||
6.5 | 6.9 | 8.5 | 8.5 | 288 | 216 | 144 | 72 | 36 | 18 | |
7.0 | 7.4 | 9.0 | 9.1 | 268 | 201 | 134 | 67 | 33 | 16 | |
8.0 | 8.5 | 10.1 | 10.4 | 232 | 174 | 116 | 58 | 29 | 14 | |
9.0 | 10.2 | 11.8 | 12.6 | 196 | 147 | 98 | 49 | 24 | 12 | |
10.0 | 10.9 | 12.5 | 13.4 | 180 | 135 | 90 | 45 | 22 | 11 | |
11.0 | 12.7 | 14.3 | 15.6 | 160 | 120 | 80 | 40 | 20 | 10 | |
12.0 | 13.2 | 14.8 | 16.3 | 152 | 114 | 76 | 38 | 19 | 9 |
The "actual" measurements on the large diameter sizes above were made after closing the ring with my pliers, tight and flush without any gaps. The bigger the diameter of the ring, the more the coil of wire can "spring back" from the mandrel which it's coiled on, causing the ring, and thus the ID and OD to be larger than the mandrel size. Please note that I still label the rings by the size of the mandrel they were coiled on (or it would be too confusing!)
Inner diameter is the diameter of the mandrel, or steel rod that I coil the wire onto before cutting into rings. Some springback will occur, making the inner diameter of the ring slightly larger than the mandrel diameter. Inner and outer diameter may be +/- .2mm from these calculations.
For more jump ring information please see the Jump Ring Info page.