The Right AQL Setting Protects Your Order

Set the AQL too loose and defective units reach your customers. Set it too tight and you reject sound lots, delay shipments and pay for re-inspections that were never needed. The tables below show how inspectors convert your order quantity and defect tolerance into an exact sample size and pass/fail line — the same logic our inspectors apply on site, independent of the factory that made the goods.

What Is the Acceptable Quality Limit?

The Acceptable Quality Limit (AQL) defines the worst defect rate you are willing to accept in a random sample, expressed as a percentage. Inspectors sample to that limit under ISO 2859-1 — the international twin of ANSI/ASQ Z1.4: if the defects found stay at or below the accept point, the lot passes; at or above the reject point, it fails. Most buyers set separate AQLs for critical, major and minor defects — critical is very commonly set to zero.

Why Sampling Beats 100% Checking (and When It Doesn’t)

• A statistical sample gives a defensible pass/fail answer at a fraction of the cost of checking every unit.
• Risk and effort scale with lot size automatically — bigger orders draw bigger samples, not linearly punishing cost.
• Each defect class carries its own limit, so cosmetic issues never veto a shipment while safety faults never slip through.
• For zero-defect commitments, safety-critical goods or high-value units, 100% inspection at our Dongguan base remains the honest alternative — see rework, assembly and warehousing.

Worked Example: 2,000 Electric Kettles, Level II, AQL 2.5

1. Find the lot: 2,000 units falls in the 1,201–3,200 row of Table A. Under General Inspection Level II this gives code letter K.
2. Find the letter in Table B: code K means a sample of 125 units.
3. Read across to your AQL: at 2.5 the row shows accept 7 / reject 8.
4. On site, the inspector randomly draws 125 kettles across cartons. Seven or fewer major defects: the lot ships. Eight or more: it fails and you decide — rework, sort or hold.

AQL Sampling Calculator

How to Read Table A: Lot Size → Code Letter

Table A converts your order quantity into a code letter, adjusted by how strict an inspection level you choose. Level II is the default for consumer goods; Level I samples less for trusted suppliers; Level III samples more after failures or for premium lines.

How to Read Table B: Code Letter → Sample Size & Accept/Reject

Table B turns the code letter into the numbers that matter on inspection day: how many units to open, and where the pass line sits for each AQL. Figures below cover normal inspection, single sampling, AQL 0.65 through 6.5.

Cells read accept / reject. For lots and letters beyond these columns the standard applies arrows and switching rules — your coordinator sets them when the booking is confirmed.

Choosing AQLs by Defect Class

• Critical — safety, regulatory or compliance failures. Most buyers set AQL 0: a single critical defect fails the lot.
• Major — faults a customer would return the product for. AQL 2.5 is the working default for general consumer goods; AQL 1.0 suits higher-risk or higher-price lines.
• Minor — small cosmetic marks buyers tolerate. AQL 4.0 is common; tighten to 2.5 for gift-grade or boxed retail.

What Happens When a Lot Fails

Every failed sample is photographed and classified in the report you receive within 24 hours. From there the decision is yours: have the factory correct and book a re-inspection at the standard man-day rate, or route the goods to our Dongguan base for sorting, rework and 100% re-check before release.

AQL Questions We Hear Often

Do I need one AQL for the whole order?

No — critical, major and minor defects each take their own limit inside the same inspection. That is precisely how our checklists are built.

Is the factory’s own QC enough?

The people who made the defects are the worst placed to judge them. An independent inspector paid by you, not the factory, is the reason third-party AQL inspection exists.

Can the sample really represent 20,000 units?

Drawn randomly across the lot, yes — that is the mathematics ISO 2859-1 is built on. What breaks it is a sample the factory pre-picks, which is why our inspectors select cartons themselves.

Can I use custom criteria instead of standard AQL?

Always. Bring your own checklist, limit samples or golden sample and the inspection runs against yours; AQL only sets the sample size and the pass line.

Have CGF Run Your AQL Inspection

Send the order quantity, product and target AQLs: a fixed-fee plan with sample sizes comes back within one working day. Inspectors operate across China, reports in Chinese or English within 24 hours — get a quote.