An open ring is sized by gently squeezing the band to close the gap or easing it apart to widen it, in small steps, while holding the band at both sides. Do it once or twice, not every day. Metal weakens when it is bent back and forth, and a plated band can crack at the bend.
Open rings are sold as adjustable, which is true within limits. The gap at the back lets the band move a little, usually about one size either way. Pushed further, the shape distorts or the plating breaks. Knowing the inner diameter before buying saves most of the adjusting.
How do you adjust an open ring?
Hold the ring with the top facing you, one thumb and finger on each side of the band, and press both sides together evenly to make it smaller, or ease them apart to make it larger. Move a little, try it on, and stop when it fits.
Take off other rings and work over a soft surface. Hold the band at both sides, never by the stone, shell or pearl on top. Squeeze or ease the band in a small, even movement. Try it on, and repeat only if needed. Leave it at that size instead of adjusting it for every wear.
Do not use pliers on a plated band. Their jaws can scratch the plating and bend the band at one point instead of along its curve.
How much can an open ring be adjusted?
About one ring size either way is a safe range for most open bands. Wikipedia's entry on ring size gives the US scale as whole sizes that differ by 0.81 mm of internal diameter, with a size 6 at 16.51 mm and a size 7 at 17.32 mm. A band that is about 17 mm inside therefore sits between those two sizes before any adjusting. Moving it by one size means closing or opening the gap by under a millimeter of diameter, which is a small movement. Larger changes are where an open band starts to lose its round shape.
| US ring size | Inner diameter | Source |
|---|---|---|
| 5 | 15.70 mm | Wikipedia, ring size |
| 6 | 16.51 mm | Wikipedia, ring size |
| 7 | 17.32 mm | Wikipedia, ring size |
| 8 | 18.14 mm | Wikipedia, ring size |
The inner size of four open rings
Each of these rings is open at the back and lists its inner size or band width on its product page, and the figures here come from those pages. The Pleated Pearl Ring is an open gold-tone band crumpled into pleats, with a row of small white freshwater cultured pearls along the fold. Its inner diameter is about 1.7 cm, the band is 1.1 cm wide, and it weighs 6 g, in 18K gold-plated copper. A wide band like this feels tighter than a slim one at the same diameter. The Pearl Flower Ring sets one flower of silver-plated copper wire, crocheted by hand around a freshwater cultured pearl, on a slim 18K gold-plated brass band that is 1.7 cm inside, open and adjustable. It weighs 4 g. The Open Oval Ring has mismatched ends, an oval of white agate or tiger's eye on one and a flat polished tip on the other, and weighs 5 g. The Shell Clover Ring sets four petals of mother-of-pearl on a band about 1.7 cm across. The rest are in the rings collection.
Does a wide band fit differently from a slim one?
Yes. A wide band covers more of the finger, so it feels snug at a diameter where a slim band feels loose, and it can be harder to pass over the knuckle. If a slim ring of the same diameter fits well, a wide one may need easing open slightly. Wire pieces on top, like the crocheted flower on a slim band, do not change the fit, but they should not be pressed while the band is adjusted. More on how crocheted wire is made is in what wire crochet jewelry is.
When should an open ring not be adjusted?
Leave it alone if the band already shows a crack, if the plating has worn thin at the back, or if the change needed is more than about one size. Bending a cracked band finishes the break. For shell and stone tops, check that nothing is loose first. For how shell differs from pearl, see mother-of-pearl vs pearl.
FAQ
Can an open ring be worn on any finger?
Within its range, yes. The same ring can move between a middle finger and an index finger if the two are close in size. Ease it open for the larger finger and closed again for the smaller one, but avoid switching every day, because each bend tires the metal.
Why does my open ring keep slipping?
The gap may have opened with wear, or the ring sits between sizes. Close it slightly with an even squeeze from both sides. If it slips round so that the top turns to the palm, a band that is wider or a size smaller will sit straighter.
Can an open ring turn into a closed ring?
Not at home. Closing the gap for good means soldering, which heats the band and can damage plating, shell and pearl. A closed ring in the right size is the simpler answer.