ASTM A1077/A1077M-21

Standard Specification for Structural Steel with Improved Yield Strength at High Temperature for Use in Buildings

SCOPE
1.1 This specification covers alloy steel in bars, plates up to and including 4 in. [100 mm] in thickness and shapes of structural quality with improved yield strength at high temperature. Two grades, 36 [250] and 50 [345] are available for use in bolted or welded buildings or for general structural purposes. Class 2 requires a maximum yield to tensile ratio – this ratio is not required for Class 1.  
1.2 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.  
1.3 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 are not exact equivalents; therefore, each system is to be used independently of the other, without combining values in any way.  
1.4 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.  
1.5 For structural products produced from coil and furnished without heat treatment or with stress relieving only, the additional requirements, including additional testing requirements and the reporting of additional test results, of Specification A6/A6M apply.  
1.6 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.  
1.7 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-Aug-2021
• ICS: 77.140.20 - Stainless steels
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.02 - Structural Steel for Bridges, Buildings, Rolling Stock and Ships

Relations

• 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 E8/E8M-24 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Jan-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 A673/A673M-17 - Standard Specification for Sampling Procedure for Impact Testing of Structural Steel
• Effective Date: 15-Nov-2017
• Refers: ASTM A370-17a - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• 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 E8/E8M-16 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 15-Jul-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 E8/E8M-15 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Feb-2015
• Refers: ASTM A370-14 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-May-2014

Overview

ASTM A1077/A1077M-21 is the international standard specification for structural steel with improved yield strength at high temperature, specifically designed for use in buildings. Developed by ASTM International, this standard covers alloy steel bars, plates (up to and including 4 in. [100 mm] thick), and shapes of structural quality. The material is available in two grades, 36 [250] and 50 [345], with the latter providing higher yield strength. This steel is intended for both bolted and welded structures and for general structural applications.

By specifying yield strength at elevated temperatures, the standard supports safer building designs, especially where fire safety and elevated temperature exposure are critical. The document provides chemical and mechanical property requirements, weldability guidance, and supplementary requirements for additional testing or restrictions as specified by purchasers.

Key Topics

• Grades and Classes:

  • Grade 36 [250] and Grade 50 [345] are available.
  • Class 1 and Class 2 define the requirements for yield-to-tensile strength ratios, with Class 2 imposing a maximum ratio for enhanced performance.

• Product Forms: Bars, plates, and structural shapes up to 4 in. [100 mm] thickness.

• High Temperature Performance:

  • Minimum yield strengths at 1110°F [600°C] specified for each grade.
  • Focus on maintaining strength in fire or other high-heat scenarios.

• Mechanical Properties:

  • Minimum tensile strength, yield point, elongation, and impact energy for both grades.
  • Charpy V-notch impact testing at 32°F [0°C] ensures material toughness.

• Chemical Composition:

  • Strict limits on carbon and alloying elements for consistency, weldability, and elevated temperature resistance.
  • Maximum Pcm carbon equivalent values provided for each grade.

• Weldability:

  • Recommendations for suitable welding procedures based on intended application.
  • Reference to ASTM A6/A6M for further weldability guidelines.

• Testing and Certification:

  • Requirements for mechanical and chemical testing, including elevated temperature tensile testing and through-thickness testing when required.
  • Supplementary and additional testing can be specified in purchase agreements.

Applications

ASTM A1077/A1077M-21 is widely used in:

• Commercial and Residential Buildings: For structural frames, beams, columns, and load-bearing elements where improved yield strength at high temperature enhances fire safety.
• Public Infrastructure: In critical facilities such as hospitals, schools, and transport terminals, where structural integrity during a fire is paramount.
• Industrial Structures: In factories, warehouses, and facilities exposed to elevated temperatures or fire risk.
• General Structural Purposes: Suitable for any steel structure demanding a guaranteed performance at elevated temperatures.

The specification supports engineers, architects, and fabricators in selecting appropriate high-strength structural steel to meet modern building codes and fire protection requirements.

Related Standards

For comprehensive project specifications or additional requirements, reference the following related ASTM standards:

• ASTM A6/A6M: General requirements for rolled structural steel bars, plates, shapes, and sheet piling.
• ASTM A370: Methods and definitions for mechanical testing of steel products.
• ASTM A673/A673M: Sampling procedure for impact testing of structural steel.
• ASTM A770/A770M: Through-thickness tension testing of steel plates for special applications.
• ASTM E8/E8M: Test methods for tension testing of metallic materials.
• ASTM E21: Test methods for conducting tension tests of metallic materials at elevated temperatures.

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Keywords: structural steel, improved yield strength, high-temperature steel, ASTM A1077, fire-resistant steel, building steel specification, alloy steel plates, structural steel bars, welded construction, bolted construction, steel standards.

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:A1077/A1077M −21
Standard Specification for
Structural Steel with Improved Yield Strength at High
Temperature for Use in Buildings
This standard is issued under the fixed designation A1077/A1077M; 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* Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1.1 This specification covers alloy steel in bars, plates up to
Barriers to Trade (TBT) Committee.
and including 4 in. [100 mm] in thickness and shapes of
structural quality with improved yield strength at high tem-
2. Referenced Documents
perature. Two grades, 36 [250] and 50 [345] are available for
2.1 ASTM Standards:
use in bolted or welded buildings or for general structural
A6/A6M Specification for General Requirements for Rolled
purposes. Class 2 requires a maximum yield to tensile ratio –
Structural Steel Bars, Plates, Shapes, and Sheet Piling
this ratio is not required for Class 1.
A370 Test Methods and Definitions for Mechanical Testing
1.2 When the steel is to be welded, a welding procedure
of Steel Products
suitable for the grade of steel and intended use or service is to
A673/A673M Specification for Sampling Procedure for Im-
be utilized. See Appendix X3 of Specification A6/A6M for
pact Testing of Structural Steel
information on weldability.
A770/A770M Specification for Through-Thickness Tension
1.3 The values stated in either inch-pound units or SI units
Testing of Steel Plates for Special Applications
are to be regarded separately as standard. Within the text, the
E8/E8M Test Methods for Tension Testing of Metallic Ma-
SI units are shown in brackets. The values stated in each
terials
system are not exact equivalents; therefore, each system is to
E21 TestMethodsforElevatedTemperatureTensionTestsof
be used independently of the other, without combining values
Metallic Materials
in any way.
3. General Requirements for Delivery
1.4 Thetextofthisspecificationcontainsnotesorfootnotes,
3.1 Products furnished under this specification shall con-
or both, that provide explanatory material. Such notes and
form to the requirements of the current edition of Specification
footnotes, excluding those in tables and figures, do not contain
A6/A6M, for the specific structural product ordered, unless a
any mandatory requirements.
conflict exists in which case this specification shall prevail.
1.5 For structural products produced from coil and fur-
3.2 Coils are excluded from qualification to this specifica-
nished without heat treatment or with stress relieving only, the
tion until they are processed into a finished structural product.
additional requirements, including additional testing require-
Structural products produced from coil means structural prod-
ments and the reporting of additional test results, of Specifi-
ucts that have been cut to individual lengths from a coil. The
cation A6/A6M apply.
processor directly controls, or is responsible for, the operations
1.6 Supplementary requirements are provided for use where
involved in the processing of a coil into a finished structural
additional testing or additional restrictions are required by the
product. Such operations include decoiling, leveling or
purchaser. Such requirements apply only when specified in the
straightening, hot-forming or cold-forming (if applicable),
purchase order.
cutting to length, testing, inspection, conditioning, heat treat-
1.7 This international standard was developed in accor-
ment(ifapplicable),packaging,marking,loadingforshipment,
dance with internationally recognized principles on standard-
and certification.
ization established in the Decision on Principles for the
NOTE 1—For structural products produced from coil and furnished
without heat treatment or with stress relieving only, two test results are to
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 Sept. 1, 2021. Published September 2021. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2012. Last previous edition approved in 2014 as A1077/A1077M – 14. Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/A1077_A1077M-21. 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
A1077/A1077M−21
be reported for each qualifying coil. Additional requirements regarding
8. Elevated Temperature Tension Test for Yield
structural products produced from coil are described in Specification
8.1 Conduct the elevated-temperature tensile test at 1110°F
A6/A6M.
[600°C].
4. Materials and Manufacture 8.1.1 The test results of 0.2 % offset yield strength shall
conform to the following values for Grade 36 [250] and 50
4.1 The steel shall be killed, and this shall be confirmed by
[345]:
one of the following statements: (1) killed steel,(2) the silicon
8.1.1.1 Grade 36 [250]: minimum 24 ksi [165 MPa]
content is 0.10 % or more, (3) the total aluminum content is
8.1.1.2 Grade 50 [345]: minimum 33 ksi [230 MPa]
0.015 % or more, or (4) the titanium content is 0.006 % or
more. 8.2 The elevated-temperature strength of the steel shall be
determined by an elevated-temperature tensile test that con-
5. Chemical Composition
forms to Test Methods E21.
5.1 The heat analysis shall conform to the requirements
8.3 Sampling:
given in Table 1.
8.3.1 Conform to the relevant section of Specification A6/
A6M, except that full-section specimens need not be used.
5.2 The steel shall conform
...

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: A1077/A1077M − 14 A1077/A1077M − 21
Standard Specification for
Structural Steel with Improved Yield Strength at High
Temperature for Use in Buildings
This standard is issued under the fixed designation A1077/A1077M; 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 alloy steel in bars, plates up to and including 4 in. [100 mm] in thickness and shapes of structural
quality with improved yield strength at high temperature. Two grades, 36 [250] and 50 [345] are available for use in bolted or
welded buildings or for general structural purposes. Class 2 requires a maximum yield to tensile ratio – this ratio is not required
for Class 1.
1.2 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.
1.3 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 are not exact equivalents; therefore, each system is to be used
independently of the other, without combining values in any way.
1.4 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.
1.5 For structural products produced from coil and furnished without heat treatment or with stress relieving only, the additional
requirements, including additional testing requirements and the reporting of additional test results, of Specification A6/A6M apply.
1.6 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.
1.7 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
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, 2014Sept. 1, 2021. Published October 2014September 2021. Originally approved in 2012. Last previous edition approved in 20122014
as A1077A1077/A1077M – 12.14. DOI: 10.1520/A1077_A1077M-14.10.1520/A1077_A1077M-21.
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
A1077/A1077M − 21
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
E8E8/E8M Test Methods for Tension Testing of Metallic Materials [Metric] E0008_E0008M
E21 Test Methods for Elevated Temperature Tension Tests of Metallic Materials
3. General Requirements for Delivery
3.1 Products furnished under this specification shall conform to the requirements of the current edition of Specification A6/A6M,
for the specific structural product ordered, unless a conflict exists in which case this specification shall prevail.
3.2 Coils are excluded from qualification to this specification until they are processed into a finished structural product. Structural
products produced from coil means structural products that have been cut to individual lengths from a coil. The processor directly
controls, or is responsible for, the operations involved in the processing of a coil into a finished structural product. Such operations
include decoiling, leveling or straightening, hot-forming or cold-forming (if applicable), cutting to length, testing, inspection,
conditioning, heat treatment (if applicable), packaging, marking, loading for shipment, and certification.
NOTE 1—For structural products produced from coil and furnished without heat treatment or with stress relieving only, two test results are to be reported
for each qualifying coil. Additional requirements regarding structural products produced from coil are described in Specification A6/A6M.
4. Materials and Manufacture
4.1 The steel shall be killed, and this shall be confirmed by one of the following statements: (1) killed steel, (2) the silicon content
is 0.10 % or more, (3) the total aluminum content is 0.015 % or more, or (4) the titanium content is 0.006 % or more.
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 Pcm carbon equivalent values shall be:
Grade Pcm Value, max %
36 [250] 0.26
50 [345] 0.29
TABLE 1 Chemical Requirements (Heat Analysis)
Product Shapes Plates Bars
Grade 36 [250] 50 [345] 36 [250] 50 [345] 36 [250] 50 [345]
Product Shapes Plates Bars
Grade 36 [250] 50 [345] 36 [250] 50 [345] 36 [250] 50 [345]
Carbon, max % 0.15 0.15 0.15 0.15 0.15 0.15
Manganese, max % 0.50 – 1.40 0.50 – 1.40 0.50 – 1.40 0.50 – 1.40 0.50 – 1.40 0.50 – 1.40
Manganese, % 0.50 – 1.40 0.50 – 1.40 0.50 – 1.40 0.50 – 1.40 0.50 – 1.40 0.50 – 1.40
Phosphorus, max % 0.035 0.035 0.030 0.030 0.035 0.035
Sulfur, max % 0.035 0.035 0.030 0.030
...