Sample size code letters

Lot  size

General inspection levels

Special inspection levels

Ⅰ

Ⅱ

Ⅲ

S1

S2

S3

S4

2 to 8

A

A

B

A

A

A

A

9 to 15

A

B

C

A

A

A

A

16 to 25

B

C

D

A

A

B

B

26 to 50

C

D

E

A

B

B

C

51 to 90

C

E

F

B

B

C

C

91 to 150

D

F

G

B

B

C

D

151 to 280

E

G

H

B

C

D

E

281 to 500

F

H

J

B

C

D

E

501 to 1200

G

J

K

C

C

E

F

1201 to 3200

H

K

L

C

D

E

G

3201 to 10000

J

L

M

C

D

F

G

10001 to 35000

K

M

N

C

D

F

H

35001 to 150000

L

N

P

D

E

G

J

150001 to 500000

M

P

Q

D

E

G

J

500001 and over

N

Q

R

D

E

H

K