How Rings Are Sized Up or Down: Bench Procedure

Customers assume a resized ring is gently stretched or squeezed. It is not. Sizing is a surgical cut: the shank is opened, a measured amount of metal is removed or added, and the piece is soldered and refinished. Done well, the joint disappears. Done badly, the ring comes back with a visible line, a lumpy round, or a solder joint that cracks within months.

Step one: measure and mark

The bench starts by checking the ring on a set of mandrels and with a wide band gauge, because a narrow gauge reads differently on a wide shank. The target size is recorded, and the cut point is chosen on the lower shank — away from engravings, stones, stamps, and gallery work. The cut line is marked with a fine scribe.

Sizing down: removing a segment

To make a ring smaller, the saw cuts out a wedge of shank. The wedge width is calculated from the circumference difference between current and target size — roughly 0.4–0.6 millimeters of shank width per full US size on a medium band. The two ends are brought together, aligned on the outside and inside, and held in a ring clamp. A small chip of matching alloy solder is placed at the joint and flowed with a fine torch. After pickling, the joint is filed flush on both inside and outside and brought back to round on a mandrel.

Sizing up: adding stock

To make a ring larger, the shank is sawed open and a strip of matching alloy — same karat, same color — is inserted to fill the gap. Adding more than about one full size on a plain shank is usually fine; adding two or more creates tension and changes the shank’s curvature, so the bench may instead swap in a new, longer section of shank rather than stretch the existing one. White gold additions require matching the alloy carefully because white solder flows at a different temperature than yellow.

What has to come off first

Before the torch comes out, stones are evaluated. Opals, emeralds, pearls, turquoise, heat-treated stones, and most included gems should be removed from the setting before any soldering, because heat travels through the shank and cracks or discolors them. Prongs are protected with a damp guard or heat shield. Engraved areas near the joint are usually left in place but refinished afterward; oxidized finishes burn off and have to be redone.

Refinishing the joint

After soldering, the joint is filed flush, sanded through a grit sequence, and polished to match the surrounding finish. On a mirror shank this is straightforward. On a brushed or hammered shank, the bench has to recreate the texture direction across the joint — this is where a careless resize shows, as a circular patch of different finish. On rhodium-plated white gold, the whole ring usually gets re-plated after sizing because the solder joint is yellow-toned and would show through.

Which rings cannot be sized

Eternity bands with stones wrapping the full circumference — any cut hits a stone.
Tension settings that rely on engineered spring pressure — cutting the shank breaks the tension design.
Mosaic or inlaid shanks with wood, bone, or resin — the heat destroys the inlay.
Fully engraved shanks where a cut line would destroy a name or date.
Vintage pieces with handmade solder joints that a modern resize would devalue.

For those, the alternatives are sizing beads (small bumps soldered inside the shank to take up a half-size) or a sizing insert that pops in and out. These are compromises, not true resizes, and they should be presented that way to the customer.

How far is too far

A plain shank can typically move up or down two to three sizes safely, depending on band width. Beyond that, the bench should rebuild the shank rather than stretch it. Buyers who send a ring back for a second resize on the same joint are asking for a crack — at that point, the shank should be replaced, not resized again.

Comfort fit and wide bands

Comfort-fit shanks have a rounded inner wall, and resizing them changes that curvature. A resize on a comfort-fit ring usually requires the inner wall to be reshaped after soldering, or the ring will feel flat where the joint sits. Wide bands (over 5 millimeters) also measure differently on standard mandrels — a wide band that reads as size 7 on a narrow gauge may actually fit like a 7.5. The bench accounts for this during the cut, which is why resizing a wide comfort-fit band takes longer than a thin flat band and should be quoted accordingly.

Our ring size guide covers how customers measure themselves at home. The takeaway: sizing is a deliberate rebuild, and the workshop that tells you upfront which of your rings cannot be sized is the one worth trusting with the rest.

Rhodium plating, which gives white gold jewellery its bright finish, is covered in the Wikipedia article on rhodium.

Frequently Asked Questions

What ring sizes can you supply in bulk?

US sizes 5–12 including half sizes. Send a size breakdown with your order and we cast to that curve; comfort-fit inner bands reduce resize requests.

Can I order a mixed size run instead of one size?

Yes. Mixed runs are standard for wholesale: specify quantity per size and we pack and label by size at no extra labor cost.

What is the MOQ for custom ring designs?

50 pieces per design for existing molds; 100–300 pieces when a new mold or CAD model is required.

How should I price rings for retail margin?

Most partners use a 3–4x markup on FOB cost for sterling and 2.5–3x for moissanite solos, which keeps landed cost under 30% of retail.

How Rings Are Sized Up or Down: The Bench Procedure