American
AISI
Type No

% Cr
Chromium

% Ni
Nickel

% Cr
Carbon

% Mn
Manganese

% Si
Silicon

% Other
N Nitrogen : Mo Molybdenum
Ti Titanium : Se Selinium
Nb Niobium : S Sulphur

201

16-18

3.5-5.5

≤ 0.15

5.5-7.5

≤ 1

≤ N 0.25

202

17-19

4-6

≤ 0.15

7.5-10

≤ 1

≤ N 0.25

301

16-18

6-8

≤ 0.15

≤ 2

≤ 1

-

302

17-19

8-10

≤ 0.15

≤ 2

≤ 1

-

302B

17-19

8-10

≤ 0.15

≤ 2

2-3

-

303

17-19

8-10

≤ 0.15

≤ 2

≤ 1

≥ S 0.15

303Se

17-19

8-10

≤ 0.15

≤ 2

≤ 1

≥ Se 0.15

304

18-20

8-12

≤ 0.08

≤ 2

≤ 1

-

304L

18-20

8-12

≤ 0.03

≤ 2

≤ 1

-

305

17-19

10-13

≤ 0.12

≤ 2

≤ 1

-

308

19-21

10-12

≤ 0.08

≤ 2

≤ 1

-

309

22-24

12-15

≤ 0.20

≤ 2

≤ 1

-

309S

22-24

12-15

≤ 0.08

≤ 2

≤ 1

-

310

24-26

19-22

≤ 0.25

≤ 2

≤ 1.5

-

310S

24-26

19-22

≤ 0.08

≤ 2

≤ 1.5

-

314

23-26

19-22

≤ 0.25

≤ 2

1.5-3

-

316

16-18

10-14

≤ 0.08

≤ 2

≤ 1

Mo 2-3

316L

16-18

10-14

≤ 0.03

≤ 2

≤ 1

Mo 2-3

317

18-20

11-15

≤ 0.08

≤ 2

≤ 1

Mo 2-3

321

17-19

9-12

≤ 0.08

≤ 2

≤ 1

≥ Ti (5 X C)

347

17-19

9-13

≤ 0.08

≤ 2

≤ 1

≥ Nb + Ta (10 X C)

348

17-19

9-13

≤ 0.08

≤ 2

≤ 1

≤ Ta 0.1 & ≤ Co 0.2

403

11.5-13

-

≤ 0.15

≤ 0.5

-

405

11.5-14.5

-

≤ 0.08

≤ 1

≤ 1

Al 0.1-0.3

410

11.5-13.5

-

≤ 0.15

≤ 1

≤ 1

-

414

11.5-13.5

1.25-2.5

≤ 0.15

≤ 1

≤ 1

-

416

12-14

-

≤ 0.15

≤ 1.25

≤ 1

≥ S 0.15

416Se

12-14

-

≤ 0.15

≤ 1.25

≤ 1

≥ S 0.15

420

12-14

-

 > 0.15

≤ 1

≤ 1

-

430

14-18

-

≤ 0.12

≤ 1

≤ 1

-

14-18

-

≤ 0.12

≤ 1.25

≤ 1

≥ S 0.15

430F Se

14-18

-

≤ 0.12

≤ 1.25

≤ 1

≥ Se 0.15

431

15-17

1.25-2.5

≤ 0.20

≤ 1

≤ 1

-

440A

16-18

-

0.6-0.75

≤ 1

≤ 1

≤ Mo 0.75

440B

16-18

-

0.75-0.95

≤ 1

≤ 1

≤ Mo 0.75

440C

16-18

-

0.95-1.2

≤ 1

≤ 1

≤ Mo 0.75

442

18-23

-

≤ 0.20

≤ 1

≤ 1

-

446