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Home › Quality Inspection › AQL Sampling Calculator & Protocol Engine
Core Quality Control

Pre-Shipment Inspection

Comprehensive physical factory audit before releasing the final 70% wire transfer.

Deliverables

35-Page Sample Report

Download real forensic audit PDF with 60+ HD photos and pass/fail logs.

QC Benchmarks

Defect Library

Critical, Major & Minor defect library across 24 major industrial sectors.

● Statistical Tool

AQL Sampling Calculator

ISO 2859-1 & ANSI/ASQ Z1.4 statistical sample code and Ac/Re limits.

ISO 2859-1 & ANSI/ASQ Z1.4 Standard

Professional AQL 2.5 / 4.0 Sampling Calculator & Protocol Engine

Amazon FBA & Retail Import Standard

Determine statistically certified sample pull quantities, sample code letters, and maximum allowable critical, major, and minor defects for your China production batch. Generate on-site testing protocols and simulate real-time Pass/Fail verdicts.

🤖 AI Custom Inspection Directive & On-Site Testing SOP
AI Engine Online

Enter your specific product name or category below. Our AI quality engineering model will generate a binding on-site inspection protocol with category-specific stress tests, custom defect tolerances, and a permanent shareable dossier for your manufacturer.

1. Configure Inspection Parameters

2. Sampling Breakdown & Pass / Fail Limits

Sample Code Letter: Letter K
Required Sample Size: 125 Units
Critical Defects: 0 (Ac:0 / Re:1)
Major Defects: 7 (Ac:7 / Re:8)
Minor Defects: 10 (Ac:10 / Re:11)

⚡ Live Inspection Result Simulator (Test Your Batch)

INSPECTION VERDICT: PASSED (Safe to Release Balance)
AQL ACCEPTED
Book On-Site Inspection for This Batch ($199 / Day) →

Standard AQL II Reference Table

ISO 2859-1 (Normal Single Sampling Plan, General Level II):

Lot Size Code Sample Maj (2.5) Min (4.0)
91 - 150F20Ac:1 / Re:2Ac:2 / Re:3
151 - 280G32Ac:2 / Re:3Ac:3 / Re:4
281 - 500H50Ac:3 / Re:4Ac:5 / Re:6
501 - 1,200J80Ac:5 / Re:6Ac:7 / Re:8
1,201 - 3,200K125Ac:7 / Re:8Ac:10 / Re:11
3,201 - 10,000L200Ac:10 / Re:11Ac:14 / Re:15
10,001 - 35,000M315Ac:14 / Re:15Ac:21 / Re:22
35,001 - 150,000N500Ac:21 / Re:22Ac:21 / Re:22

Defect Threshold Rules

1. Critical (0.0): Zero Tolerance

Safety, electrical, sharp burrs, or choking hazards. Even 1 critical unit results in immediate batch rejection.

2. Major (2.5): Usability Failures

Impairments affecting product function, assembly, or unscannable barcodes that cause Amazon FBA warehouse rejections.

3. Minor (4.0): Aesthetic Flaws

Surface scratches, light color variance, or cosmetic scuffs that do not reduce functionality.

AI INSPECTION DIRECTIVE ENGINE Ready

Generate Tailored On-Site Testing SOP & Permanent Protocol Dossier

Don't rely only on generic numbers. Enter your exact product below. Our AI engine correlates your order volume (3,000 units) with international standards (ASTM, FDA, LFGB, EN71, CE) to generate on-site stress tests, defect classification matrices, factory risk advisories, and generates a permanent, shareable QC protocol dossier.

Instant Benchmark Shortcuts

Common Production Order Batches (Quick AQL Sampling Rules)

Pre-calculated AQL Level II sampling thresholds for the most frequent Amazon FBA and container procurement volumes.

500 Units Batch Code Letter H
• Sample Pull: 50 Units (10% of batch)
• Critical (0.0): 0 Max (Ac:0 / Re:1)
• Major (2.5): 3 Max (Ac:3 / Re:4)
• Minor (4.0): 5 Max (Ac:5 / Re:6)
1,000 Units Batch Code Letter J
• Sample Pull: 80 Units (8% of batch)
• Critical (0.0): 0 Max (Ac:0 / Re:1)
• Major (2.5): 5 Max (Ac:5 / Re:6)
• Minor (4.0): 7 Max (Ac:7 / Re:8)
3,000 Units (FBA Core) Code Letter K
• Sample Pull: 125 Units (4.1% of batch)
• Critical (0.0): 0 Max (Ac:0 / Re:1)
• Major (2.5): 7 Max (Ac:7 / Re:8)
• Minor (4.0): 10 Max (Ac:10 / Re:11)
5,000 Units Batch Code Letter L
• Sample Pull: 200 Units (4% of batch)
• Critical (0.0): 0 Max (Ac:0 / Re:1)
• Major (2.5): 10 Max (Ac:10 / Re:11)
• Minor (4.0): 14 Max (Ac:14 / Re:15)
10,000 Units (FCL Container) Code Letter M
• Sample Pull: 315 Units (3.1% of batch)
• Critical (0.0): 0 Max (Ac:0 / Re:1)
• Major (2.5): 14 Max (Ac:14 / Re:15)
• Minor (4.0): 21 Max (Ac:21 / Re:22)
50,000 Units (Mega Run) Code Letter N
• Sample Pull: 500 Units (1% of batch)
• Critical (0.0): 0 Max (Ac:0 / Re:1)
• Major (2.5): 21 Max (Ac:21 / Re:22)
• Minor (4.0): 21 Max (Ac:21 / Re:22)
Official ISO Reference Matrix

Full ISO 2859-1 (ANSI/ASQ Z1.4) Normal Single Sampling Plan Table

Complete statistical lookup matrix for General Inspection Levels I, II, and III with AQL 1.5, 2.5, and 4.0 acceptance (Ac) and rejection (Re) numbers.

Batch Size (Units) Level I Level II (Standard) Level III Sample Size (n) AQL 1.5 (Ac / Re) AQL 2.5 (Major) AQL 4.0 (Minor)
2 to 8AAB2Ac:0 / Re:1Ac:0 / Re:1Ac:0 / Re:1
9 to 15ABC3Ac:0 / Re:1Ac:0 / Re:1Ac:0 / Re:1
16 to 25BCD5Ac:0 / Re:1Ac:0 / Re:1Ac:0 / Re:1
26 to 50CDE8Ac:0 / Re:1Ac:0 / Re:1Ac:1 / Re:2
51 to 90CEF13Ac:0 / Re:1Ac:1 / Re:2Ac:1 / Re:2
91 to 150DFG20Ac:1 / Re:2Ac:1 / Re:2Ac:2 / Re:3
151 to 280EGH32Ac:1 / Re:2Ac:2 / Re:3Ac:3 / Re:4
281 to 500FHJ50Ac:2 / Re:3Ac:3 / Re:4Ac:5 / Re:6
501 to 1,200GJK80Ac:3 / Re:4Ac:5 / Re:6Ac:7 / Re:8
1,201 to 3,200HKL125Ac:5 / Re:6Ac:7 / Re:8Ac:10 / Re:11
3,201 to 10,000JLM200Ac:7 / Re:8Ac:10 / Re:11Ac:14 / Re:15
10,001 to 35,000KMN315Ac:10 / Re:11Ac:14 / Re:15Ac:21 / Re:22
35,001 to 150,000LNP500Ac:14 / Re:15Ac:21 / Re:22Ac:21 / Re:22
150,001 to 500,000MPQ800Ac:21 / Re:22Ac:21 / Re:22Ac:21 / Re:22
500,001 & overNQR1,250Ac:21 / Re:22Ac:21 / Re:22Ac:21 / Re:22
Manufacturing Sector Standards

Product-Specific Defect Classification Protocols (By Category)

Real-world examples of how certified inspectors classify defects across China's primary export manufacturing sectors.

📱 3C Consumer Electronics & Audio

  • Critical (0): Electrical shock hazard, reverse polarity, battery bulging during charging test, ungrounded metal chassis.
  • Major (2.5): Bluetooth pairing failure, speaker audio distortion at 80% volume, dead pixels on display, USB-C port loose connection.
  • Minor (4.0): Micro-scratch on matte plastic bezel, minor silk-screen logo misalignment (<1mm), slight LED light bleed.

👶 Apparel, Kids Wear & Softlines

  • Critical (0): Needle fragment detected in metal detector, detached baby snap button (choking hazard), toxic dye odor.
  • Major (2.5): Open seam or broken stitches, size tolerance exceeding +/- 1.5cm, zipper jam, significant shading between panels.
  • Minor (4.0): Loose threads not trimmed (<1cm), minor fabric slub, slight creasing from packaging fold.

☕ Kitchenware, Drinkware & Cookware

  • Critical (0): Sharp rim on metal tumbler lip, heavy metal migration, peeling internal non-stick PTFE coating.
  • Major (2.5): Vacuum insulation failure (outer wall hot with boiling water), leak test failure during 360° inversion, wobbly bottom base.
  • Minor (4.0): Pinhead-sized dust point under powder coating, silicone gasket slight water stain mark, minor gift box dent.

🔩 Industrial Machinery & CNC Hardware

  • Critical (0): Internal casting crack or porosity, thread pitch mismatch causing binding, missing safety interlock.
  • Major (2.5): Critical dimension out of tolerance (>0.05mm), failed salt-spray corrosion test, motor overheating in 30min load test.
  • Minor (4.0): Minor chamfer unevenness, non-functional surface tool marks, oil stain on packaging wrapper.
Expert Guidance

Frequently Asked Questions About AQL Sampling in China

Critical answers to help international importers master quality inspections, dispute resolution, and factory accountability.

What is AQL in China factory quality inspection?

AQL (Acceptance Quality Limit) is defined by ISO 2859-1 and ANSI/ASQ Z1.4 as the maximum percentage of defective units considered satisfactory as a process average. Instead of examining 100% of an order, certified quality inspectors pull a statistically valid random sample based on batch size to determine whether the entire shipment should be accepted or rejected.

What does AQL 2.5 mean for Amazon FBA sellers?

AQL 2.5 is the standard threshold for Major defects adopted by global retailers and Amazon FBA sellers. For instance, in an order of 3,000 units inspected under General Level II (Sample Code Letter K, 125 units sampled), the batch passes if 7 or fewer major defects are found (Ac:7), and fails if 8 or more are detected (Re:8).

What is the difference between Critical, Major, and Minor defects?

Critical defects (AQL 0.0) involve safety, fire, or regulatory hazards (e.g. sharp burrs, toxic chemicals, electrical leakage); even 1 critical unit results in instant batch rejection. Major defects (AQL 2.5) impair product functionality, structural integrity, or barcode scannability. Minor defects (AQL 4.0) represent cosmetic imperfections that do not diminish operational usability.

Which inspection level should I choose: Level I, II, or III?

General Inspection Level II is the universal benchmark for over 90% of commercial consumer goods. Level I uses a reduced sample size (approx. 40% of Level II) recommended for trusted, long-term suppliers. Level III pulls a tightened sample (approx. 160% of Level II) suitable for high-value electronics, luxury merchandise, or factories with prior quality disputes.

What happens if my production batch fails the AQL inspection?

If an inspection fails, the buyer holds the final wire balance payment (typically 70%). The factory manager signs the on-site inspection report, acknowledging the defect count. The supplier must unbox the inventory, conduct 100% sorting and rework, and schedule a re-inspection. Under standard procurement agreements, the supplier pays the re-inspection fee.

How many units are sampled for an order of 5,000 pieces?

Under General Level II, 5,000 units fall into the 3,201 - 10,000 range (Sample Code Letter L). Exactly 200 units must be randomly pulled from master cartons. Limits are: 0 Critical, maximum 10 Major, and maximum 14 Minor defects allowed before batch rejection.