A chain in Dublin used a paper ring sizer and customers measured at home and ordered a half size small in 31% of cases. The order was not lost on price. It was lost on a specification nobody wrote down. This piece looks at oem from the buyer's side of the table: what the promise means at the bench, what it costs to get it wrong, and how to write a brief a factory can be held to.
Why Size Returns Outnumber Quality Returns
Sizing is a merchandising decision disguised as a technical one. The wrong size chart costs more than a plating defect because it converts a sale into a return and a refund.
We publish the inside diameter in millimetres on every piece and supply a sizer that reads in the same unit, so the customer is choosing a number rather than a letter.
What the Industry Standard Delivers, and Where It Breaks
The default offer in this category is a stock photo, a unit price and a thirty-day promise. That works for one order and stops working on the second, because a stock photo cannot specify 10k.
| Comparison | Common practice | What we hold | Why it matters |
|---|---|---|---|
| Region | Common size system | Conversion risk | |
| United States | numeric 5-9 | letter mapping differs by brand | |
| United Kingdom | letter A-Z | half sizes not universal | |
| EU | circumference mm | most reliable | |
| Asia | diameter mm | close to EU but not equal |
How We Take the Guesswork Out of OEM Sizing
Karat assay on a finished piece is the number we publish per lot. It is the one a buyer can check with a caliper and a loupe in ten minutes, and the one that decides whether a reorder is a formality or a negotiation.
- Lot and rack reference on every carton
- 10k declared on the invoice, not assumed
- One plated sample approved per rack before the run
- Stone parcel photographed and hue band stated in writing
Packaging and the First Thirty Seconds
The carton is the first physical impression. An anti-tarnish pouch, a cavity insert and a stone-side-up orientation cost a few cents and prevent most of the transit damage we see on gold pieces.
Loose fill is the main cause of bent posts and scratched faces. It is cheaper than a cavity insert by about two cents a unit, which is the worst trade in the category.
Why We Publish the Numbers
Publishing karat assay on a finished piece and the plating micron figure is uncomfortable for a factory that expects to be judged on photographs. It is comfortable for a buyer who has to defend a reorder to a boss.
The number is the argument. A supplier who will not publish one is asking you to trust the photograph instead.
The Three Failure Modes We See Most
On gold pieces the three failures that come back most often are porosity from gas in the casting, colour mismatch between the casting and the findings, and under-karat alloy. Each has a root cause upstream of the bench, which is why sorting finished pieces never fixes the rate.
Prong wear traces to wire gauge and setting pressure. Stone tilt traces to the bearing surface being cut by hand instead of by burr. Plating burn-off traces to rack contact points, not to the tank.
Tolerance Stack: Where 0.1mm Becomes a Complaint
Tolerance compounds across operations. A casting that runs 0.15mm wide, a setting that shifts the stone 0.1mm, and a polish that removes 0.05mm of surface can put a gold piece outside the size the customer ordered without any single step being out of specification.
That is why we hold the stack at the casting rather than at the finish. Tightening the last operation cannot recover tolerance that was already spent at the first.
The Reorder Sheet We Hand Back
Every reorder comes back with the original sheet: alloy batch, stone parcel reference, plating rack number, setting team, measured karat assay on a finished piece. It is four lines and it removes the argument about what "the same" means.
Buyers who keep those four lines can audit a fifth lot in an afternoon. Buyers who do not are comparing two photographs and hoping.
Packaging and the First Thirty Seconds
The carton is the first physical impression. An anti-tarnish pouch, a cavity insert and a stone-side-up orientation cost a few cents and prevent most of the transit damage we see on gold pieces.
Loose fill is the main cause of bent posts and scratched faces. It is cheaper than a cavity insert by about two cents a unit, which is the worst trade in the category.
What We Will Not Do, and Why That Protects You
We will not quote from a stock photo, we will not promise a date the plating queue cannot hold, and we will not sell a design we made exclusively for one buyer to another buyer.
Each of those is a short-term sale and a long-term loss, and the loss lands on the buyer who trusted the quote. Saying no to them is the cheapest quality control we operate.
Why We Ask for the Tolerance Before the Drawing
A tolerance stated after the drawing is a complaint waiting to happen. State it before and it becomes a manufacturing instruction, which is a very different conversation at the bench.
Most disputes we see are not about quality. They are about two people who each thought the other had agreed to a number that nobody wrote down.
What Changes Between Lot One and Lot Five
Repeatability depends on four inputs staying fixed: the alloy batch, the stone parcel, the plating tank and the setting team. Swap any one of them to save cost and the fifth lot looks like a different product to your customer.
We keep the lot record for all four, so a reorder is compared against your first lot rather than against a photograph on a website.
What We Will Not Do, and Why That Protects You
We will not quote from a stock photo, we will not promise a date the plating queue cannot hold, and we will not sell a design we made exclusively for one buyer to another buyer.
Each of those is a short-term sale and a long-term loss, and the loss lands on the buyer who trusted the quote. Saying no to them is the cheapest quality control we operate.
What It Costs and How Long It Takes
Fifty pieces per design is the working minimum on oem. A sample runs three to five days, bulk fifteen to twenty days under 500 pieces, and a custom mould twenty-five to thirty days from drawing approval. Payment is 30% deposit with the balance against the bill of lading copy.
If the order is below fifty, the setup cost per piece roughly doubles because the casting tree and the plating rack are fixed costs. That is arithmetic, not a policy to negotiate around.
| Item | Value | Note |
|---|---|---|
| MOQ | 50 pcs / design | sizes and colours can be split |
| Sample | 3-5 days | one piece, approved before the run |
| Bulk lead time | 15-20 days | under 500 pieces |
| Custom lead time | 25-30 days | from drawing approval |
| Payment | 30% / 70% | balance against B/L copy |
| Port | Guangzhou / Shenzhen | export from Wuzhou |
Frequently Asked Questions
How do I convert US sizes to mm?
A US size 7 is 17.3mm inside diameter. We print the millimetre figure on the spec sheet and on the product page, because a conversion table that rounds to 17mm causes half-size disputes.
Can you supply a ring sizer?
Yes, a multi-step gauge that reads direct in millimetres, packed with the sample. It costs less than one exchange.
Do you offer half sizes?
In 0.5 steps from size 4 to 9 on the casting, without a surcharge above fifty pieces. Full sizes only on some bands because the mould is shared.
What if the customer is between sizes?
Recommend the larger size on a wide band and the smaller on a narrow one. Band width changes how a size feels by up to half a size.
Can you produce a second lot identical to the first?
Yes, if we hold the four inputs: alloy batch, stone parcel, plating tank and setting team. The reorder sheet records all four, so the check happens against a document rather than against a memory.
What happens if the lot arrives outside the agreed tolerance?
Photograph the piece with a scale and reference the lot line. Above the agreed AQL we replace and cover freight; inside it we replace the affected units inside ten days.
About the Manufacturer
HOLYCOME by Wuzhou HengliLai Jewelry Co., Ltd. runs casting, setting, polishing and plating on one site in Wuzhou, Guangxi, the artificial gemstone cluster that supplies most of the trade. Monthly capacity is roughly 60,000 pieces across silver and gold lines. Buyers can reach the trade desk at service@holycome.com or on WhatsApp at +86 18078079070, and a factory visit can be arranged with two weeks' notice.
Next Step
If you are pricing oem for a season, send the quantity per design, the stone grade you need and the date you need it on the shelf. We will return a drawing, a landed cost and a production date within three days, and a physical sample before you commit to a run. Samples are charged at cost and credited against the first order.
Related reading: Necklace Factory China Guide 2026 - HOLYCOME, Bulk Necklace Production Capacity Supplier - HOLYCOME, Wholesale Necklace Qc - HOLYCOME
