ASTM A400-23
(Practice)Standard Practice for Steel Bars, Selection Guide, Composition, and Mechanical Properties
Standard Practice for Steel Bars, Selection Guide, Composition, and Mechanical Properties
SIGNIFICANCE AND USE
4.1 If the desired mechanical properties are as described in 5.1.1 for material identified as Classes P-1 through P-7, or in 5.1.2 for material identified as Classes Q-1 through Q-7, the strength level desired can be based on hardness or the equivalent tensile or yield strength as shown in Tables 1-4. If the desired mechanical properties are as set forth in 5.1.3 for material identified as Classes R-1 through R-6, the strength level is based on yield strength as shown in Tables 5 and 6.
4.2 The user, after determining the mechanical property requirements of the critical section (that carrying the greatest stress) of the part, should select the composition or compositions from Tables 1-6 that fulfills these requirements and is most suitable for processing.
SCOPE
1.1 This practice covers the selection of steel bars according to section and to the mechanical properties desired in the part to be produced. This is not a specification for the procurement of steel. Applicable procurement specifications are listed in Section 6.
1.2 Several steel compositions intended for various sections and mechanical property requirements are presented in Tables 1-6. The criteria for placing a steel composition in one of the three general class designations, Classes P, Q, and R (described in Section 5) are as follows:
1.2.1 Classes P and Q should be capable of developing the mechanical properties shown in Tables 1-4 by liquid quenching from a suitable austenitizing temperature, and tempering at 800 °F (427 °C) or higher. A hardness indicated by tests made at a location shown in Fig. 1, A, B, or C, is taken as evidence that a composition is capable of meeting other equivalent mechanical properties shown in the tables. Normal good shop practices are assumed, with control of austenitizing and tempering temperatures, and mild agitation of the part in the quenching bath.
FIG. 1 Locations in Typical Cross Sections of Steel Bars at Which Desired Properties Are Obtained
1.2.2 Class R should be capable of developing the mechanical properties shown in Tables 5 and 6 as hot rolled, by cold drawing, or by cold drawing with additional thermal treatment. The locations for obtaining tension tests are described in 7.2.
1.3 It is not implied that the compositions listed in the tables are the only ones satisfactory for a certain class and mechanical property requirement. Steels with lower alloy contents are often satisfactory through the use of special processing techniques.
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: A400 − 23
Standard Practice for
Steel Bars, Selection Guide, Composition, and Mechanical
1
Properties
This standard is issued under the fixed designation A400; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This practice covers the selection of steel bars according
ization established in the Decision on Principles for the
to section and to the mechanical properties desired in the part
Development of International Standards, Guides and Recom-
to be produced. This is not a specification for the procurement
mendations issued by the World Trade Organization Technical
of steel. Applicable procurement specifications are listed in
Barriers to Trade (TBT) Committee.
Section 6.
1.2 Several steel compositions intended for various sections
2. Referenced Documents
and mechanical property requirements are presented in Tables
2
2.1 ASTM Standards:
1-6. The criteria for placing a steel composition in one of the
A108 Specification for Steel Bar, Carbon and Alloy, Cold-
three general class designations, Classes P, Q, and R (described
Finished
in Section 5) are as follows:
A304 Specification for Carbon and Alloy Steel Bars Subject
1.2.1 Classes P and Q should be capable of developing the
to End-Quench Hardenability Requirements
mechanical properties shown in Tables 1-4 by liquid quenching
A311/A311M Specification for Cold-Drawn, Stress-
from a suitable austenitizing temperature, and tempering at
Relieved Carbon Steel Bars Subject to Mechanical Prop-
800 °F (427 °C) or higher. A hardness indicated by tests made
erty Requirements
at a location shown in Fig. 1, A, B, or C, is taken as evidence
A322 Specification for Steel Bars, Alloy, Standard Grades
that a composition is capable of meeting other equivalent
A633/A633M Specification for Normalized High-Strength
mechanical properties shown in the tables. Normal good shop
Low-Alloy Structural Steel Plates
practices are assumed, with control of austenitizing and tem-
A675/A675M Specification for Steel Bars, Carbon, Hot-
pering temperatures, and mild agitation of the part in the
Wrought, Special Quality, Mechanical Properties
quenching bath.
A941 Terminology Relating to Steel, Stainless Steel, Related
1.2.2 Class R should be capable of developing the mechani-
Alloys, and Ferroalloys
cal properties shown in Tables 5 and 6 as hot rolled, by cold
drawing, or by cold drawing with additional thermal treatment.
3. Terminology
The locations for obtaining tension tests are described in 7.2.
3.1 Definitions—For definitions of terms used in this
1.3 It is not implied that the compositions listed in the tables
standard, refer to Terminology A941.
are the only ones satisfactory for a certain class and mechanical
property requirement. Steels with lower alloy contents are
4. Significance and Use
often satisfactory through the use of special processing tech-
4.1 If the desired mechanical properties are as described in
niques.
5.1.1 for material identified as Classes P-1 through P-7, or in
1.4 The values stated in inch-pound units are to be regarded
5.1.2 for material identified as Classes Q-1 through Q-7, the
as standard. The values given in parentheses are mathematical
strength level desired can be based on hardness or the
conversions to SI units that are provided for information only
equivalent tensile or yield strength as shown in Tables 1-4. If
and are not considered standard.
the desired mechanical properties are as set forth in 5.1.3 for
1
This practice is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
2
A01.15 on Bars. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2023. Published November 2023. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1956. Last previous edition approved in 2017 as A400 – 17. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/A0400-23. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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A400 − 23
TABLE 1 Steels f
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: A400 − 17 A400 − 23
Standard Practice for
Steel Bars, Selection Guide, Composition, and Mechanical
1
Properties
This standard is issued under the fixed designation A400; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*Scope
1.1 This practice covers the selection of steel bars according to section and to the mechanical properties desired in the part to be
produced. This is not a specification for the procurement of steel. Applicable procurement specifications are listed in Section 56.
1.2 Several steel compositions intended for various sections and mechanical property requirements are presented in Tables 1-6.
The criteria for placing a steel composition in one of the three general class designations, Classes P, Q, and R (described in Section
45) are as follows:
1.2.1 Classes P and Q should be capable of developing the mechanical properties shown in Tables 1-4 by liquid quenching from
a suitable austenitizing temperature, and tempering at 800 °F (427 °C) or higher. A hardness indicated by tests made at a location
shown in Fig. 1, A, B, or C, is taken as evidence that a composition is capable of meeting other equivalent mechanical properties
shown in the tables. Normal good shop practices are assumed, with control of austenitizing and tempering temperatures, and mild
agitation of the part in the quenching bath.
1.2.2 Class R should be capable of developing the mechanical properties shown in Tables 5 and 6 as hot rolled, by cold drawing,
or by cold drawing with additional thermal treatment. The locations for obtaining tension tests are described in 6.27.2.
1.3 It is not implied that the compositions listed in the tables are the only ones satisfactory for a certain class and mechanical
property requirement. Steels with lower alloy contents are often satisfactory through the use of special processing techniques.
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
1
This practice is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.15
on Bars.
Current edition approved Nov. 1, 2017Nov. 1, 2023. Published December 2017November 2023. Originally approved in 1956. Last previous edition approved in 20122017
as A400 – 69 (2012).A400 – 17. DOI: 10.1520/A0400-17.10.1520/A0400-23.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
A400 − 23
TABLE 1 Steels for Moderately Quenched Parts—Classes P-1 Through P-7
(Applicable to oil-quenching or equivalent rate of heat-removal.)
NOTE 1—Steels listed as approved for a certain section or strength may be used for lighter sections and lower strengths.
NOTE 2—Steel composition numbers correspond to SAE or ASTM designations. Those in italics are no longer considered standard grades due to
decreased usage.
NOTE 3—An H-steel with the same grade designation as a standard SAE steel is capable of meeting the same section and strength requirements as the
standard steel (see Specification A304), and is the preferred method of specification.
NOTE 4—Steels having a maximum carbon content of 0.40 % or over, or a hardness of HB 293 or over after heat-treating, are not recommended for
applications involving welding.
Class
P-1 P-2 P-3 P-4 P-5 P-6 P-7
Diameter of Round
...
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