We specialize in precious metal jump rings at Spiderchain, but it can be nice to have a lower cost material for testing out design ideas. I reach for these copper jump rings when I’m testing gold filled sizes. We make our copper rings to the same quality standards as our gold filled rings, and the size match is quite good. The copper runs just a tiny bit smaller than the gold filled, usually not enough to notice any difference. Your gold filled design might come out slightly more flexible than the copper test, but you won’t run out of room weaving the rings together.
21ga Jump Rings – inch
|Inner Diameter||Rings per Troy Ounce|
Please note that the inner diameter listed is the size of the steel rod that we use to wind that ring size. The finished size will be a tiny bit larger (especially for big/thin rings) because the wire springs back a bit after being wrapped around the rod. And if you want rings with even larger inner diameters than are listed here, please visit the Large Aspect Ratio section of the site.
The rings/ozt numbers in this chart will be closest for sterling silver jump rings. The other metals that we use are slightly less dense than sterling silver. If you’re buying gold filled, brass or copper rings you will get a few more rings in an ounce than you see in the chart.
General Info About Copper
These rings are made from pure copper, which is usually very soft. Soft rings make weak chainmaille, so I collaborated with a wire mill to get copper wire that’s as springy and tough as it’s possible for copper to be. They produce “extra spring hard” copper wire for me that has been run through a draw plate to work harden it as far as pure copper will harden. There is a limit to the work hardening of pure copper (and pure silver and pure gold) so these copper jump rings aren’t quite as springy as half-hard sterling (my standard) and the ring sizes come out just a tad smaller due to the smaller springback. But it’s close.
Work hardening and annealing are two important processes in metallurgy. Work hardening is the process of making a metal stronger by deforming it. Annealing is the process of relieving stress and making a metal softer by heating it and then allowing it to cool slowly. Wikipedia has some great information about the theory and applications of work hardening and annealing in metallurgy.
Copper tarnishes quickly to form a soft patina that many find appealing. If you prefer your copper chainmaille to be new-penny shiny, tumble with stainless shot for 10 minutes in water that contains a few squirts of distilled vinegar. Remove from the tumbler, rinse, and then air dry.
Working with 21 Gauge Jump Rings
Dainty, detailed, and a little bit delicate, 21ga jump rings are a good choice for earrings and necklaces. This wire size can be lovely for bracelets as well, but I recommend sticking with weaves that use smaller aspect ratio sizes to give the finished chain more strength. Birdcage (AKA Byzantine) is a fantastic choice for 21ga bracelets. You’ll probably want to use two pairs of chain-nose pliers for working with 21ga rings, but maybe keep a pair of flat-nose pliers nearby just in case.