AQL ChartSample size code letters (Table I)
Find the row for your lot size, then read across to the inspection level. The letter tells you which row of the sampling table to use.
| Lot size | Special levels | General levels | |||||
|---|---|---|---|---|---|---|---|
| S-1 | S-2 | S-3 | S-4 | I | II | III | |
| 2–8 | A | A | A | A | A | A | B |
| 9–15 | A | A | A | A | A | B | C |
| 16–25 | A | A | B | B | B | C | D |
| 26–50 | A | B | B | C | C | D | E |
| 51–90 | B | B | C | C | C | E | F |
| 91–150 | B | B | C | D | D | F | G |
| 151–280 | B | C | D | E | E | G | H |
| 281–500 | B | C | D | E | F | H | J |
| 501–1,200 | C | C | E | F | G | J | K |
| 1,201–3,200 | C | D | E | G | H | K | L |
| 3,201–10,000 | C | D | F | G | J | L | M |
| 10,001–35,000 | C | D | F | H | K | M | N |
| 35,001–150,000 | D | E | G | J | L | N | P |
| 150,001–500,000 | D | E | G | J | M | P | Q |
| 500,001 and over | D | E | H | K | N | Q | R |
Sample size for each code letter (single sampling, normal inspection)
| Code letter | A | B | C | D | E | F | G | H | J | K | L | M | N | P | Q | R |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sample size | 2 | 3 | 5 | 8 | 13 | 20 | 32 | 50 | 80 | 125 | 200 | 315 | 500 | 800 | 1,250 | 2,000 |
If the sample size equals or exceeds the lot or batch size, do 100 percent inspection.
Single sampling plans for normal inspection (Table II-A) · AQL sampling calculator
Source and limits
Values on this site are transcribed from MIL-STD-105E, Sampling Procedures and Tables for Inspection by Attributes (U.S. Department of Defense, 10 May 1989), Tables I and II-A. Every cell was read from the page scans and then compared by script with a second, separately keyed copy of the tables.
This is a reference tool. It covers single sampling under normal inspection only — not tightened or reduced inspection, and not double or multiple sampling. It has not been compared cell by cell with the current paid editions of ANSI/ASQ Z1.4 or ISO 2859-1. The standard named in your contract or purchase order, in the edition it names, is what governs.