Jump ring size guide: what size jump ring for charms?

For most charms, use a 5mm or 6mm jump ring in 0.7mm wire. Go smaller for tiny charms and earrings, and bigger and thicker for heavy pendants and bag charms. The rest of this page explains how to pick the right one for the charm in your hand.

Reading a jump ring size

Jump rings are sold as two numbers, for example 6mm x 0.7mm. The first is the outer diameter of the ring; the second is the wire thickness (sometimes called the gauge — 0.7mm is roughly 21 gauge). What actually matters when you join things is the space inside the ring:

inner diameter = outer diameter − (2 × wire thickness)

So a 6mm x 0.7mm ring has about 4.6mm of usable space inside, and a 4mm x 0.7mm ring only about 2.6mm.

Size chart by charm

These are starting points, not rules — the two checks below decide it.

The two checks that decide it

1. The wire must fit through the charm's loop. Look at the hole the charm hangs from. 0.7mm wire passes through almost every Tibetan silver charm loop; thicker 1mm+ wire may not fit small charms, so check before you buy thick rings for little charms.
2. The inside of the ring must hold everything it joins, with room to swing. The ring has to go round the charm's loop and the chain link or bracelet link, and still leave a little slack so the charm hangs flat and moves freely. If the charm sits sideways or looks pinched, go up a size.

Thin wire, big ring = weak ring

A large ring made from thin wire bends open easily. If a ring keeps pulling open, use thicker wire, a smaller ring, two rings side by side (a "double jump ring"), or a split ring, which can't open on its own. Heavy charms on bags and keys almost always want a split ring.

How to open and close a jump ring

1. Hold the ring with two pairs of pliers (or one pair and a jump ring tool), with the split at the top.
2. Twist one side towards you and the other away — never pull the ends apart sideways. Pulling distorts the circle and it will never close properly.
3. Slip on the charm and the chain link.
4. Twist back until the ends meet flush. Going very slightly past and back again work-hardens the wire and helps it stay shut.

Questions

What size jump ring should I use for charms?

For most standard charms, 5mm to 6mm jump rings in 0.7mm wire. Small charms and earrings suit 4mm to 5mm; large or heavy pendants need 7mm to 10mm rings in thicker wire, or a split ring.

What does 6mm x 0.7mm mean on a jump ring?

The first number is the outer diameter of the ring and the second is the thickness of the wire. The usable inside of a 6mm x 0.7mm ring is about 4.6mm (6 minus twice 0.7).

Why does my jump ring keep pulling open?

The wire is too thin for the ring size or the weight of the charm, or the ring was opened by pulling the ends apart. Use thicker wire, a smaller ring, a double jump ring or a split ring, and always open rings with a sideways twist.