Ring sizing on a jeweler's bench and ring sizing in a production factory are different jobs. A bench resize is a repair on a finished customer piece; a factory size run is a planned distribution across a whole production order. Confusing the two leads buyers to expect bench-level resizing prices on wholesale runs, and to expect factory-level consistency on a one-off resize. The two workflows have different cost structures and different durability outcomes.
Why factories plan size ranges up front
When a buyer places a wholesale order for 100 rings, the factory does not cast 100 identical rings and then size them. It asks for a size distribution up front: say 30 in size 6, 40 in size 7, 20 in size 8, 10 in size 9. The CAD or wax is scaled in the model room for each size band, and the castings come out near the target size. Final sizing is a light touch rather than a major surgery. This is faster, cheaper, and far more durable than sizing a finished ring up or down several sizes, because scaling the CAD preserves wall thickness, stone seat geometry, and shank proportions. A ring stretched or cut up two sizes on the bench loses wall thickness and looks different from the sample.
Cut-add vs. stretch
When a finished ring must be resized, the standard method is cut-add: the shank is cut, a measured piece of sizing stock is inserted, and the joint is soldered, filed, and polished. Stretching the shank on a stretching machine works only for small adjustments on simple bands and only in softer alloys; it thins the wall and is not used on set rings, engraved bands, or karat gold that work-hardens. A factory that offers stretch sizing as a standard option is cutting corners on durability. Cut-add leaves a visible joint line when done poorly; a good cut-add joint disappears into the finish and survives years of wear because the added stock matches the surrounding metal.
Matching the sizing stock to the alloy
Sizing stock must match the base metal in karat and color. Sizing a 14k yellow gold ring with 14k yellow stock; a white gold ring gets white gold stock, and the joint then goes back through rhodium plating. Using a higher-karat stock on a lower-karat ring creates a galvanic mismatch that can discolor the seam; using a lower-karat stock weakens the joint. Good factories keep a shelf of matched stock by alloy and color, often in wire or strip form ready to cut to length. Ask to see that shelf when you audit; a factory that keeps one universal "gold" wire is a repair shop, not a production line.
Post-size finishing
A size-adjusted ring is never shipped straight from the solder joint. It goes back through the finishing station: the solder seam is filed flush, the surrounding surface is re-sanded, and the piece is re-polished so the joint disappears. On engraved or textured bands, the finisher has to re-create the texture by hand, which adds bench time. Buyers asking for large-size runs of engraved rings should expect a per-piece premium for this re-texturing step. A ring that ships with a visible solder line is not a finished resize; it is a rejected resize.
When a ring cannot be sized
Not every ring can be resized cleanly. Full-eternity bands with stones all the way around, rings with hidden hinges, and pieces with cracked or thin shanks often cannot be sized without rebuilding. Factories flag these at intake and tell the buyer up front; a factory that agrees to resize an eternity band without warning about stone removal and re-seating is setting itself up for a return. A good rule of thumb: if more than a quarter of the shank is set with stones, size distribution has to be locked before casting, not adjusted afterward.
Half sizes, widths, and comfort fit
Ring sizing is not a single number on a stick gauge. A size 7 in a 2mm flat band fits differently than a size 7 in a 6mm comfort-fit band, because the internal profile changes how the band slides over the knuckle. Factories keep width and profile on the spec sheet so the size run lands consistently. Comfort-fit bands, with a rounded inner wall, sit looser than flat bands at the same stamped size; a buyer who has not specified profile will receive a mix that feels inconsistent across the run. Half sizes are produced the same way as full sizes, by scaling the CAD, rather than by stretching a full-size casting.
Planning your size order
For wholesale orders, send the size distribution with the PO rather than after casting. Confirm that the factory uses matched sizing stock and re-polishes after solder. Ask what their oversize and undersize tolerance is on castings; a tight tolerance means less final sizing labor per piece. You can read about how we size on our sizing guides.
The Wikipedia article on rhodium explains why rhodium plating is applied to white gold and silver jewellery.
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.
