ASTM A304-11 - 1.10.2011
 
1. Scope

1.1 This specification covers hot-worked alloy, carbon, and carbon-boron steels in a variety of compositions and sizes, which may attain specified depth of hardening in the end quench test. These steel compositions are identified by the suffix letter “H” added to the conventional grade number.

1.2 This specification provides for analyses other than those listed under Tables 1 and 2. Special hardenability limits are also permissible when approved by the purchaser and manufacturer.

1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.

TABLE 2 Chemical Requirements of Carbon H-SteelsA

UNS DesignationB
Grade Designation
Chemical Composition, %
Carbon
Manganese
Phosphorus,
max
Sulfur,
max
Silicon

H 10380

1038 H

0.34–0.43

0.50–1.00

0.040

0.050

0.15–0.35

H 10450

1045 H

0.42–0.51

0.50–1.00

0.040

0.050

0.15–0.35

H 15220

1522 H

0.17–0.25

1.00–1.50

0.040

0.050

0.15–0.35

H 15240

1524 H

0.18–0.26

1.25–1.75

0.040

0.050

0.15–0.35

H 15260

1526 H†

0.21–0.30

1.00–1.50

0.040

0.050

0.15–0.35

H 15410

1541 H

0.35–0.45

1.25–1.75

0.040

0.050

0.15–0.35

H 15211C

15B21 HC

0.17–0.24

0.70–1.20

0.040

0.050

0.15–0.35

H 15351C

15B35 HC

0.31–0.39

0.70–1.20

0.040

0.050

0.15–0.35

H 15371C

15B37 HC

0.30–0.39

1.00–1.50

0.040

0.050

0.15–0.35

H 15411C

15B41 HC

0.35–0.45

1.25–1.75

0.040

0.050

0.15–0.35

H 15481C

15B48 HC

0.43–0.53

1.00–1.50

0.040

0.050

0.15–0.35

H 15621C

15B62 HC

0.54–0.67

1.00–1.50

0.040

0.050

0.40–0.60

†Correction made editorially

A Standard H Steels can be produced with a lead range of 0.15–0.35 %. Such steels are identified by inserting the letter “L” between the second and third numerals of the grade designation, for example, 15L22 H. Lead is generally reported as a range of 0.15–0.35 %.

B New designations established in accordance with Practice E527 and SAE J 1086, Recommended Practice for Numbering Metals and Alloys (UNS).

C These steels can be expected to have 0.0005 % min boron content.

 
2. Referenced Documents

J1086

Numbering Metals and Alloys

E112-25

Standard Test Methods for Determining Average Grain Size

A255-20a

Standard Test Methods for Determining Hardenability of Steel (Includes all amendments and changes 11/16/2020).

A108-24

Standard Specification for Steel Bar, Carbon and Alloy, Cold-Finished

A29/A29M-23

Standard Specification for General Requirements for Steel Bars, Carbon and Alloy, Hot-Wrought

E527-23

Standard Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)