Quality control

How a jewelry order is actually inspected

"Strict quality control" is on every supplier's website and means nothing. What a buyer can act on is the sampling standard, the sample size at their quantity, the definition of a major defect, and what happens to a lot that fails. This page states all four.

Inspection standard

Standard: ISO 2859-1
AQL: 2.5 major / 4.0 minor
Level: General II
At 1,000 pcs: 80-piece sample

What AQL actually means

Most disputes about a jewelry shipment are really disputes about what was agreed, not about what arrived. AQL is the vocabulary that prevents that.

AQL — Acceptable Quality Limit — is a statistical sampling standard defined in ISO 2859-1. A random sample is drawn from a finished lot, the defects found are counted by class, and the lot is accepted or rejected against a published acceptance number.

AQL 2.5 does not mean 2.5% of the shipment will be faulty. It means the lot is rejected once the sample suggests the defect rate exceeds roughly 2.5%. The distinction matters because it sets expectations correctly: AQL is a decision rule for accepting a lot, not a guarantee about individual pieces.

It is also statistical rather than exhaustive. A 1,000-piece lot is judged on 80 pieces. Where every piece must be checked — high-value items, or a first order into a demanding retailer — that is 100% inspection, and it is a separate line on the quotation because it is a materially different amount of labour.

Sample sizes by order quantity

ISO 2859-1, general inspection level II, AQL 2.5 for major defects and 4.0 for minor. These numbers are from the standard and are the same at any factory using it.

AQL sample sizes and acceptance numbers by lot size
Lot size	Sample size	Major — accept	Major — reject	Minor — accept
151–280 pcs	32	2	3	3
281–500 pcs	50	3	4	5
501–1,200 pcs	80	5	6	7
1,201–3,200 pcs	125	7	8	10
3,201–10,000 pcs	200	10	11	14
10,001–35,000 pcs	315	14	15	21

Values are from ISO 2859-1 single sampling plans for normal inspection, level II, AQL 2.5 (major) and 4.0 (minor). Our standard MOQ of 500 pcs falls in the 501–1,200 band.

Defect classification

The classification is where a quality dispute is won or lost. Agreeing these definitions before production is worth more than any inspection clause afterwards.

Jewelry defect classification
Class	Definition	Jewelry examples	AQL
Critical	Unsafe, or non-compliant with a regulation	Sharp edge that can cut; nickel release above the applicable limit; lead above the Prop 65 threshold	0 — any critical defect rejects the lot
Major	A customer would notice and return the piece, or function is affected	Patchy or discoloured plating on a visible surface; loose or missing stone; clasp that opens under load; dimension outside tolerance; visible casting flaw	2.5
Minor	Cosmetic, visible only on close inspection	Faint polishing line; slight colour variation within the agreed tolerance; minor packing imperfection	4.0

Critical defects carry zero acceptance: one found in the sample rejects the lot regardless of the AQL applied to the other classes.

Critical — Torn, unfinished edge on a rim that sits against skin, pulling fibres out of an inspection glove — AQL 0, one in the sample rejects the lot — CriticalTorn, unfinished edge on a rim that sits against skin, pulling fibres out of an inspection glove — AQL 0, one in the sample rejects the lot

Major — Plating patchy and discoloured on a visible face — AQL 2.5, the class most disputes are about — MajorPlating patchy and discoloured on a visible face — AQL 2.5, the class most disputes are about

Minor — Faint polishing line, visible only on close inspection — AQL 4.0, accepted at a looser number — MinorFaint polishing line, visible only on close inspection — AQL 4.0, accepted at a looser number

When inspection happens

A final inspection alone catches problems when it is too late to fix them economically. Checking during the run is what keeps a drifting die from producing a whole lot of rejects.

STEP 01
Incoming material
Alloy grade checked against the mill certificate before it enters production.
Per delivery
STEP 02
First article
First piece off a new setup measured against the approved sample before the run continues.
Per setup
STEP 03
In-line
Checks during the run, not only at the end — a drifting die is caught in hundreds, not thousands.
Continuous
STEP 04
Post-plating
Colour, coverage and adhesion checked after the finishing batch.
Per batch
STEP 05
Final AQL
Random sample drawn from the finished lot to the agreed AQL plan.
Per lot
STEP 06
Pre-shipment
Count, packing, labelling and documentation verified against the PO.
Per shipment

01
Per delivery
Incoming material
Alloy grade checked against the mill certificate before it enters production.
02
Per setup
First article
First piece off a new setup measured against the approved sample before the run continues.
03
Continuous
In-line
Checks during the run, not only at the end — a drifting die is caught in hundreds, not thousands.
04
Per batch
Post-plating
Colour, coverage and adhesion checked after the finishing batch.
05
Per lot
Final AQL
Random sample drawn from the finished lot to the agreed AQL plan.
06
Per shipment
Pre-shipment
Count, packing, labelling and documentation verified against the PO.

Measurement and testing

What gets measured, with what, and why it is the measurement that matters commercially.

Measurement and verification methods
Property	Method	Why it matters
Dimensions	Digital calipers and gauges against the approved sample	Ring size and chain length errors are the most common cause of a returned lot
Plating thickness	X-ray fluorescence (XRF), non-destructive	The specification most often quietly reduced to hit a price. 0.1 µm and 1.0 µm look identical on arrival
Plating adhesion	Tape test and bend test on batch samples	Adhesion failure shows up after weeks of wear, not at inspection
Alloy composition	Mill certificate for the batch, XRF verification	The only way to confirm 316L rather than 304, or lead-free brass rather than C3604
Corrosion resistance	Neutral salt spray to ASTM B117	Predicts how a finish survives sweat and humidity
Nickel release	EN 1811, after EN 12472 conditioning for coated items	Required for EU sale — 0.5 µg/cm²/week skin contact, 0.2 µg/cm²/week pierced ears
Lead and cadmium	Third-party laboratory analysis	Required for California and for US children's products

Third-party testing is arranged on request. Which standards apply, what the laboratory charges and how long it takes depend on the market, the material and the batch size, so both are confirmed in writing in the quotation rather than quoted generically.

Salt spray resistance by finish (ASTM B117 neutral)
Finish	Thickness	Salt spray to first failure
Flash plating	0.05–0.175 µm	8–16 h
Standard gold plating	0.5–1.0 µm	16–24 h
Heavy gold plating	2.5–5 µm	24–48 h
Gold vermeil	≥ 2.5 µm over 925 silver	24–48 h
PVD / IP on 316L	0.3–1.0 µm	48–96 h
316L, uncoated	—	96 h+

Hours to first failure under neutral salt spray. A useful comparative indicator rather than a prediction of years of wear.

industry-typical

If a batch fails

The remedy matters less than having agreed it in advance. These are the terms.

Non-conformance remedies
Lot fails final AQL in our inspection	Sorted or reworked before shipment; the buyer is told, not surprised
Lot fails the buyer’s incoming inspection	Affected quantity remade at our cost, including freight
Critical defect found at any stage	Lot held; root cause traced to the batch and operation that produced it
Plating thickness below specification	Re-plated or remade — thickness is a measurable, not a judgement
Dispute over defect classification	Settled against the definitions agreed in the PO, which is why they belong there
Third-party inspection requested	Buyer’s inspector given the lot and the production records

Quality control questions

Each answer stands alone and can be read without the rest of this page.

What does AQL 2.5 mean for a jewelry order?

AQL — Acceptable Quality Limit — is a statistical sampling standard defined in ISO 2859-1. AQL 2.5 means a random sample is drawn from the finished lot, and the lot is accepted if the number of major defects found is at or below the plan's acceptance number, which corresponds to roughly 2.5% defective at the limit. It is not a promise that 2.5% of pieces will be faulty; it is the threshold at which a lot is rejected rather than accepted.

How many pieces are actually inspected in an AQL check?

Far fewer than most buyers expect, because AQL is statistical rather than exhaustive. Under ISO 2859-1 general inspection level II, a lot of 501–1,200 pieces takes a sample of 80, and a lot of 1,201–3,200 takes 125. At AQL 2.5 the 80-piece sample accepts on 5 major defects and rejects on 6. If you need every piece checked, that is 100% inspection and it is quoted separately.

What counts as a major defect in jewelry?

A defect that a customer would notice and return the piece for, or that affects function: plating that is discoloured, patchy or missing on a visible surface; a stone that is loose or missing; a clasp that does not close or opens under load; a dimension outside the agreed tolerance; a visible casting flaw or sharp edge. Minor defects are cosmetic imperfections visible only under close inspection, and they carry a separate, looser acceptance number.

What happens if an incoming inspection at my end fails?

If a lot fails against the AQL standard that was agreed in the purchase order, the affected quantity is remade at our cost, including freight. What makes that workable is agreeing the standard, the inspection level and the defect definitions before production — a dispute about whether something is a major or minor defect after the fact is very hard to settle without that.

Do you provide inspection reports with the shipment?

Yes — an AQL inspection report travels with the shipment, recording the lot size, sample size, inspection level, AQL, defects found by class, and the accept or reject decision. Buyers are also free to appoint their own third-party inspector; we will book the inspection date and present the lot.

How do you check plating thickness?

Plating thickness is specified in microns and verified by X-ray fluorescence, which measures the deposited layer non-destructively. This is the check that matters most commercially, because plating thickness is the specification most often quietly reduced to hit a target price — and a 0.1 µm and a 1.0 µm piece are visually identical on the day they arrive.

Not answered here? All buyer questions →

Sources

Where the standards and legal limits quoted on this page are published. Every figure traceable to one of these can be checked at the issuer rather than taken on our word.

Standards cited on this page
Designation	Published by	What it specifies
REACH Annex XVII entry 27	European Union	Nickel release limits for articles in prolonged skin contact and for pierced-ear posts
EN 1811	CEN	Reference test method for nickel release from articles in contact with the skin · not freely published; the binding limit is in REACH Annex XVII entry 27
California Proposition 65	California OEHHA	Lead and cadmium exposure warnings for products sold in California
ISO 2859-1	ISO	Sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection
ASTM B117	ASTM International	Salt spray (fog) apparatus — the corrosion test coating hours are quoted against

Every figure on this page traceable to one of these can be checked against the published standard rather than taken on our word.

Agree the standard before production, not after

Send the design and the market you ship to. The quotation states the AQL, the inspection level, the defect definitions and the testing route — so there is nothing left to argue about when the lot arrives. Production runs on our own floor in Qingxi, Dongguan, Guangdong.

01Reply within one working day, Guangdong business hours.
02Itemised cost sheet — mold quoted separately, not folded into the unit price.
03NDA on request before any file is shared.

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