ASTM A1043/A1043M-18

Standard Specification for Structural Steel with Low Yield to Tensile Ratio for Use in Buildings

SCOPE
1.1 This specification covers two grades, 36 [250] and 50 [345] of rolled steel structural shapes and plates with low yield to tensile ratio for use in building framing or for general structural purposes.  
1.2 All shape profiles with a flange width of 6 in. [150 mm] and greater described in Specification A6/A6M, Annex A2, and plates up to and including 5 in. [125 mm] thick are included in this specification.  
1.3 Supplementary requirements are provided for use where additional testing or additional restrictions are required by the purchaser. Such requirements apply only when specified in the purchase order.  
1.4 When the steel is to be welded, a welding procedure suitable for the grade of steel and intended use or service is to be utilized. See Appendix X3 of Specification A6/A6M for information on weldability.  
1.5 The text of this specification contains notes or footnotes, or both, that provide explanatory material; such notes and footnotes, excluding those in tables and figures, do not contain any mandatory requirements.  
1.6 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.  
1.7 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.

General Information

• Status: Published
• Publication Date: 31-Oct-2018
• ICS: 91.080.10 - Metal structures
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.02 - Structural Steel for Bridges, Buildings, Rolling Stock and Ships

Relations

• Replaces: ASTM A1043/A1043M-14 - Standard Specification for Structural Steel with Low Yield to Tensile Ratio for Use in Buildings
• Effective Date: 01-Nov-2018
• Refers: ASTM A370-24 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Mar-2024
• Refers: ASTM A6/A6M-24 - Standard Specification for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling
• Effective Date: 01-Mar-2024
• Refers: ASTM A6/A6M-23 - Standard Specification for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling
• Effective Date: 01-Nov-2023
• Refers: ASTM A370-19 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Jul-2019
• Refers: ASTM A370-17a - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-Nov-2017
• Refers: ASTM A673/A673M-17 - Standard Specification for Sampling Procedure for Impact Testing of Structural Steel
• Effective Date: 15-Nov-2017
• Refers: ASTM A6/A6M-17a - Standard Specification for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling
• Effective Date: 01-Nov-2017
• Refers: ASTM A370-17 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Jan-2017
• Refers: ASTM A6/A6M-16a - Standard Specification for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling
• Effective Date: 15-Nov-2016
• Refers: ASTM A6/A6M-16 - Standard Specification for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling
• Effective Date: 01-May-2016
• Refers: ASTM A370-15 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Nov-2015
• Refers: ASTM A370-14 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-May-2014
• Refers: ASTM A6/A6M-14 - Standard Specification for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling
• Effective Date: 01-May-2014
• Refers: ASTM A370-13 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-Nov-2013

Overview

ASTM A1043/A1043M-18 is a standard specification developed by ASTM International for structural steel with a low yield to tensile ratio, specifically designed for use in building construction and general structural purposes. This standard covers two principal grades, 36 [250] and 50 [345], addressing the requirements for rolled steel structural shapes and plates. The focus on a low yield to tensile ratio enhances ductility and reliability, especially in seismic or critical loading scenarios.

ASTM A1043/A1043M-18 seeks to ensure steel used in buildings meets stringent performance expectations, including chemical composition, mechanical properties, and specific supplementary requirements when additional testing or restrictions are necessary.

Key Topics

• Grades and Applications
  • Covers Grade 36 [250] and Grade 50 [345] structural steel with low yield to tensile ratios.
  • Applicable to rolled steel shapes with flange widths of 6 in. [150 mm] or greater, and plates up to 5 in. [125 mm] thick.
• Mechanical Properties
  • Minimum tensile strength: 58 ksi [400 MPa] for Grade 36 and 65 ksi [450 MPa] for Grade 50.
  • Yield to tensile ratio: maximum 0.80 for both grades, ensuring increased ductility.
  • Charpy impact testing required, with minimum average values specified.
• Chemical Composition
  • Strict maximum limits on carbon, manganese, phosphorus, sulfur, and other alloy elements to achieve the desired mechanical properties.
  • Carbon equivalent limits set for weldability and toughness, with formulas and requirements specified.
• Supplementary Requirements
  • Optional requirements for additional testing, such as vacuum treatment, ultrasonic examination, and through-thickness tension tests.
  • Purchasers may specify further restrictions for critical applications.

Applications

ASTM A1043/A1043M-18 structural steel is widely used in:

• Building Framing: The standard is tailored for steel framing in commercial, industrial, and residential buildings, where a low yield-to-tensile ratio is desirable for enhanced safety, especially in seismic designs and areas expecting dynamic loads.
• General Structural Steelwork: This specification provides assurance for projects requiring robust, reliable steel components that maintain ductility and toughness under stress.
• Welded Construction: The controlled chemical composition and carbon equivalent values support consistent weldability, making this standard ideal for steel that will require on-site or fabrication welding.

This standard is routinely required in project specifications to address both standard and demanding structural applications, ensuring long-term performance and compliance with international building codes.

Related Standards

The following ASTM standards are referenced in conjunction with ASTM A1043/A1043M-18:

• ASTM A6/A6M: General requirements for rolled structural steel bars, plates, shapes, and sheet piling.
• ASTM A370: Test methods and definitions for mechanical testing of steel products.
• ASTM A673/A673M: Sampling procedures for impact testing of structural steel.
• ASTM A770/A770M: Specifications for through-thickness tension testing of steel plates for special applications.

By adhering to ASTM A1043/A1043M-18 and its related standards, engineers, fabricators, and contractors ensure structural safety, quality, and compliance in building projects involving structural steel with low yield to tensile ratios.

Keywords: structural steel, low yield to tensile ratio, ASTM A1043, building framing, steel plates, rolled shapes, welded construction, mechanical properties, building standards, ductility.

Standards Content (Sample)

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:A1043/A1043M −18
Standard Specification for
Structural Steel with Low Yield to Tensile Ratio for Use in
Buildings
This standard is issued under the fixed designation A1043/A1043M; 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.
1. Scope* 2. Referenced Documents
1.1 This specification covers two grades, 36 [250] and 50 2.1 ASTM Standards:
[345] of rolled steel structural shapes and plates with low yield A6/A6M Specification for General Requirements for Rolled
to tensile ratio for use in building framing or for general Structural Steel Bars, Plates, Shapes, and Sheet Piling
structural purposes. A370 Test Methods and Definitions for Mechanical Testing
of Steel Products
1.2 All shape profiles with a flange width of 6 in. [150 mm]
A673/A673M Specification for Sampling Procedure for Im-
andgreaterdescribedinSpecificationA6/A6M,AnnexA2,and
pact Testing of Structural Steel
plates up to and including 5 in. [125 mm] thick are included in
A770/A770M Specification for Through-Thickness Tension
this specification.
Testing of Steel Plates for Special Applications
1.3 Supplementary requirements are provided for use where
additional testing or additional restrictions are required by the 3. General Requirements for Delivery
purchaser. Such requirements apply only when specified in the
3.1 Product furnished under this specification shall conform
purchase order.
to the requirements of the current edition of Specification
1.4 When the steel is to be welded, a welding procedure A6/A6M for the ordered product, unless a conflict exists, in
which case this specification shall prevail.
suitable for the grade of steel and intended use or service is to
be utilized. See Appendix X3 of Specification A6/A6M for
4. Materials and Manufacture
information on weldability.
4.1 The steel shall be killed, and such shall be affirmed in
1.5 The text of this specification contains notes or footnotes,
the test report by a statement of killed steel, a value of 0.10 %
or both, that provide explanatory material; such notes and
or more for the silicon content, a value of 0.015 % or more for
footnotes, excluding those in tables and figures, do not contain
the total aluminum content, or a value of 0.006 % or more for
any mandatory requirements.
the titanium content.
1.6 The values stated in either inch-pound units or SI units
are to be regarded separately as standard. Within the text, the 5. Chemical Composition
SI units are shown in brackets. The values stated in each
5.1 The heat analysis shall conform to the requirements
system may not be exact equivalents; therefore, each system
given in Table 1.
shall be used independently of the other. Combining values
5.2 The steel shall conform on product analysis to the
from the two systems may result in nonconformance with the
requirements given in Table 1, subject to the product analysis
standard.
tolerances in Specification A6/A6M.
1.7 This international standard was developed in accor-
5.3 The maximum permissible carbon equivalent values
dance with internationally recognized principles on standard-
shall be:
ization established in the Decision on Principles for the
Thickness of Plate
Development of International Standards, Guides and Recom-
Grade CE Value max %
and Shape Flange
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
36 [250] All 0.37
50 [345] #2 in. [50 mm] 0.45
50 [345] >2 in. [50 mm] 0.47
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
A01.02 on Structural Steel for Bridges, Buildings, Rolling Stock and Ships. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2018. Published November 2018. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2005. Last previous edition approved in 2014 as A1043/A1043M – 14. Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/A1043_A1043M-18. 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
A1043/A1043M−18
A
TABLE 1 Chemical Requirements (Heat Analysis) TABLE 2 Tensile Requirements
Grade
Composition, %
36 [250] 50 [345]
Element
Grade Grade
Tensile strength, min, ksi [MPa] 58 [400] 65 [450]
36 [250] 50 [345]
Yield point, ksi [MPa] 36 to 52 50 to 65
Carbon, max 2 in. [50 mm] and less in thickness 0.20 0.20
[250 to 360] [345 to 450]
Over 2 in. [50 mm] in thickness 0.22 0.22
Yield to tensile ratio, max 0.80 0.80
Manganese 0.50–1.40 0.50–1.60
B
Elongation in 8 in. [200 mm], min % 20 18
Phosphorus, max 0.030 0.030
B
Elongation in 2 in. [50 mm], min % 23 21
Sulfur, max 0.030 0.030
A
Silicon, max 0.35 0.55 See Specimen Orientation under the Tension Tests section of Specification
A6/A6M.
Nitrogen, max 0.012 0.012
B
Nickel, max 0.45 0.45 For plates wider than 24 in. [600 mm] the elongation requirement is reduced two
percentage points. See Elongation Requirement Adj
...

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: A1043/A1043M − 14 A1043/A1043M − 18
Standard Specification for
Structural Steel with Low Yield to Tensile Ratio for Use in
Buildings
This standard is issued under the fixed designation A1043/A1043M; 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.
1. Scope*
1.1 This specification covers two grades, 36 [250] and 50 [345] of rolled steel structural shapes and plates with low yield to
tensile ratio for use in building framing or for general structural purposes.
1.2 All shape profiles with a flange width of 6 in. [150 mm] and greater described in Specification A6/A6M, Annex A2, and
plates up to and including 5 in. [125 mm] thick are included in this specification.
1.3 Supplementary requirements are provided for use where additional testing or additional restrictions are required by the
purchaser. Such requirements apply only when specified in the purchase order.
1.4 When the steel is to be welded, a welding procedure suitable for the grade of steel and intended use or service is to be
utilized. See Appendix X3 of Specification A6/A6M for information on weldability.
1.5 The text of this specification contains notes or footnotes, or both, that provide explanatory material; such notes and
footnotes, excluding those in tables and figures, do not contain any mandatory requirements.
1.6 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units
are shown in brackets. The values stated in each system aremay not be exact equivalents; therefore, each system is to shall be used
independently of the other without combining values in any way.other. Combining values from the two systems may result in
nonconformance with the standard.
1.7 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
2.1 ASTM Standards:
A6/A6M Specification for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling
A370 Test Methods and Definitions for Mechanical Testing of Steel Products
A673/A673M Specification for Sampling Procedure for Impact Testing of Structural Steel
A770/A770M Specification for Through-Thickness Tension Testing of Steel Plates for Special Applications
3. General Requirements for Delivery
3.1 Product furnished under this specification shall conform to the requirements of the current edition of Specification A6/A6M
for the ordered product, unless a conflict exists, in which case this specification shall prevail.
4. Materials and Manufacture
4.1 The steel shall be killed, and such shall be affirmed in the test report by a statement of killed steel, a value of 0.10 % or more
for the silicon content, a value of 0.015 % or more for the total aluminum content, or a value of 0.006 % or more for the titanium
content.
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.02
on Structural Steel for Bridges, Buildings, Rolling Stock and Ships.
Current edition approved Oct. 1, 2014Nov. 1, 2018. Published October 20014November 2018. Originally approved in 2005. Last previous edition approved in 20092014
as A1043/A1043M – 05 (2009).A1043/A1043M – 14. DOI: 10.1520/A1043_A1043M-14.10.1520/A1043_A1043M-18.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’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
A1043/A1043M − 18
TABLE 1 Chemical Requirements (Heat Analysis)
Composition, %
Element
Grade Grade
36 [250] 50 [345]
Carbon, max 2 in. [50 mm] and less in thickness 0.20 0.20
Over 2 in. [50 mm] in thickness 0.22 0.22
Manganese 0.50–1.40 0.50–1.60
Phosphorus, max 0.030 0.030
Sulfur, max 0.030 0.030
Silicon, max 0.35 0.55
Nitrogen, max 0.012 0.012
Nickel, max 0.45 0.45
Chromium, max 0.35 0.35
Molybdenum, max 0.15 0.15
Copper, max 0.50 0.50
A A
Vanadium, max 0.15 0.15
A A
Columbium, max 0.05 0.05
B A A
Columbium (niobium), max 0.05 0.05
Titanium, max 0.03 0.03
A
The sum of columbium (niobium) and vanadium shall not exceed 0.15 %.
B
Columbium and niobium are interchangeable names for the same element.
5. Chemical Composition
5.1 The heat analysis shall conform to the requirements given in Table 1.
5.2 The steel shall conform on product analysis to the requirements given in Table 1, subject to the product analysis tolerances
in Specification A6/A6M.
5.3 The maximum permissible carbon equivalent values shall be:
Thickness of Plate
Grade CE Value max %
and Shape Flange
36 [250] All 0.37
50 [345] # 2 in. [50 mm] 0.45
50 [345] #2 in. [50 mm] 0.45
50 [345] > 2 in. [50 mm] 0.47
50 [345] >2 in. [50 mm] 0.47
5.3.1 The carbon equivalent value shall be based upon heat analysis. The required chemical analysis as well as the carbon
equivalent shall be reported. The carbon equivalent shall be calculated using the following formula:
CE 5 C1 Mn
...