ASTM B473-24

Standard Specification for Nickel-Iron-Chromium-Molybdenum-Copper Alloy Bar and Wire

ABSTRACT
This specification covers UNS N08020, UNS N08026, and UNS N08024 nickel alloy bar and wire. The alloys shall be furnished in the stabilized-annealed condition, solution-annealed condition, or annealed condition. The material shall conform to the requirements as to chemical composition prescribed. The material shall conform to the applicable requirements as to mechanical properties prescribed. Chemical analysis and tension test shall be made to conform to the requirements specified.
SCOPE
1.1 This specification2 covers UNS N08020 bar and wire other than required for reforging.  
1.2 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.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to become familiar with all hazards including those identified in the appropriate Safety Data Sheet (SDS) for this product/material as provided by the manufacturer, to establish appropriate safety, health, and environmental practices, and determine the applicability of regulatory limitations prior to use.  
1.4 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-Mar-2024
• ICS: 77.150.40 - Nickel and chromium products
• Technical Committee: B02 - Nonferrous Metals and Alloys
• Drafting Committee: B02.07 - Refined Nickel and Cobalt and Their Alloys

Relations

• Replaces: ASTM B473-07(2018) - Standard Specification for UNS N08020, UNS N08024, and UNS N08026 Nickel Alloy Bar and Wire
• Effective Date: 01-Apr-2024
• Referred By: ASTM B475-07(2018) - Standard Specification for UNS N08020, UNS N08024, and UNS N08026 Nickel Alloy Round Weaving Wire
• Effective Date: 01-Apr-2024
• Referred By: ASTM F1511-18(2023) - Standard Specification for Mechanical Seals for Shipboard Pump Applications
• Effective Date: 01-Apr-2024
• Referred By: ASTM B366/B366M-23 - Standard Specification for Factory-Made Wrought Nickel and Nickel Alloy Fittings
• Effective Date: 01-Apr-2024
• Referred By: ASTM B462-18e1 - Standard Specification for Forged or Rolled Nickel Alloy Pipe Flanges, Forged Fittings, and Valves and Parts for Corrosive High-Temperature Service
• Effective Date: 01-Apr-2024

Overview

ASTM B473-24 is the international standard specification for nickel-iron-chromium-molybdenum-copper alloy bar and wire, specifically covering materials designated as UNS N08020, UNS N08024, and UNS N08026. Issued by ASTM International, this standard provides comprehensive requirements for the manufacture, chemical composition, mechanical properties, permissible dimensional variations, and testing of specialty alloy bar and wire used in critical industrial applications. The specification ensures consistency, reliability, and quality assurance for producers and users worldwide in sectors where corrosion resistance, mechanical strength, and precise tolerances are essential.

Key Topics

• Scope of Standard: Outlines requirements for hot-finished and cold-finished bars and cold-finished wire, excluding reforging stock.
• Chemical Composition: Specifies mandatory chemical composition ranges for elements such as nickel, iron, chromium, molybdenum, copper, and others, ensuring material purity and performance.
• Condition and Heat Treatment: Defines that products must be supplied in stabilized-annealed, solution-annealed, or general annealed conditions, depending on the alloy grade.
• Mechanical Properties: Includes minimum tensile strength, yield strength, elongation, and reduction of area, ensuring the alloys meet demanding performance criteria.
• Dimensional Tolerances: Details permissible variations in diameter, thickness, width, length, and straightness for both bars and wire to guarantee compliance with exact engineering requirements.
• Test Methods: References specific ASTM methods for chemical analysis (ASTM E1473) and mechanical testing (ASTM E8/E8M).
• Ordering and Certification: Lists essential ordering requirements, including quantities, forms, dimensions, grade, finish, inspection, and certification procedures.

Applications

ASTM B473-24 is widely utilized in industries where materials are exposed to aggressive environments and high mechanical stresses. Typical uses include:

• Chemical processing equipment: Pipes, heat exchangers, and reactors benefit from these alloys' exceptional resistance to corrosion and scaling in acids and chlorides.
• Petrochemical and oil & gas industries: Valves, pumps, and related components maintain integrity and safety under extreme operational conditions.
• Food processing plants: Fabrication of sanitary equipment that must withstand cleaning agents and harsh conditions.
• Pharmaceutical manufacturing: Material choice for vessels and piping systems requiring both purity and durability.
• Environmental and pollution control: Utilized in systems handling corrosive substances and wastewater treatment.

The nickel-iron-chromium-molybdenum-copper alloys specified provide a robust combination of corrosion resistance, mechanical strength, and workability, making them ideal for these demanding environments.

Related Standards

For broader compliance and quality assurance, ASTM B473-24 references and relates to the following industry standards:

• ASTM A262: Practices for detecting susceptibility to intergranular attack in austenitic stainless steels, crucial for corrosion testing.
• ASTM B880: Specification for chemical check analysis limits for nickel and cobalt alloys.
• ASTM E8/E8M: Test methods for tension testing of metallic materials.
• ASTM E1473: Test methods for chemical analysis of nickel, cobalt, and high-temperature alloys.
• ASME SB-473: The ASME specification harmonized with ASTM B473 for boiler and pressure vessel code compliance.

Adhering to ASTM B473-24 ensures that nickel alloy bars and wire not only meet strict regulatory and safety requirements but also provide optimal long-term performance in critical applications worldwide.

Keywords: ASTM B473, nickel-iron-chromium-molybdenum-copper alloy, UNS N08020, UNS N08024, UNS N08026, alloy bar, alloy wire, corrosion resistant alloys, chemical composition standards, mechanical property requirements, industrial nickel alloys.

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: B473 − 24
Standard Specification for
Nickel-Iron-Chromium-Molybdenum-Copper Alloy Bar and
Wire
This standard is issued under the fixed designation B473; 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* for Electrical Purposes (Withdrawn 2003)
2 E8/E8M Test Methods for Tension Testing of Metallic Ma-
1.1 This specification covers UNS N08020 bar and wire
terials
other than required for reforging.
E1473 Test Methods for Chemical Analysis of Nickel,
1.2 The values stated in inch-pound units are to be regarded
Cobalt, and High-Temperature Alloys
as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only
3. Terminology
and are not considered standard.
3.1 Definitions:
1.3 This standard does not purport to address all of the
3.1.1 Definitions for terms defined in Terminology B889
safety concerns, if any, associated with its use. It is the
shall apply unless otherwise defined by the requirements of this
responsibility of the user of this standard to become familiar
document.
with all hazards including those identified in the appropriate
3.2 Definitions of Terms Specific to This Standard:
Safety Data Sheet (SDS) for this product/material as provided
3.2.1 The terms bar and wire as used in this specification are
by the manufacturer, to establish appropriate safety, health,
described as follows:
and environmental practices, and determine the applicability
3.2.2 bars, n—hot-finished rounds, squares, octagons, and
of regulatory limitations prior to use.
hexagons: ⁄4 in. (6.35 mm) and over in diameter or size.
1.4 This international standard was developed in accor-
Hot-finished flats: ⁄4 in. to 10 in. (254 mm), inclusive, in
dance with internationally recognized principles on standard-
width, ⁄8 in. (3.175 mm) and over in thickness. Cold-finished
ization established in the Decision on Principles for the
rounds, squares, octagons, hexagons, and shapes: over ⁄2 in.
Development of International Standards, Guides and Recom-
(12.7 mm) in diameter or size. Cold-finished flats: ⁄8 in. (9.525
mendations issued by the World Trade Organization Technical
mm) and over in width (see Discussion (1)), ⁄8 in. and over in
Barriers to Trade (TBT) Committee.
thickness (see Discussion (2)).
3.2.2.1 Discussion—(1) Widths less than ⁄8 in. (9.525 mm)
2. Referenced Documents 3
and thicknesses less than ⁄16 in. (4.75 mm) are generally
described as flat wire.
2.1 ASTM Standards:
3.2.2.2 Discussion—(2) Thicknesses ⁄8 in. (3.175 mm) to
A262 Practices for Detecting Susceptibility to Intergranular
under ⁄16 in. (4.75 mm) can be cold-rolled strip as well as bar.
Attack in Austenitic Stainless Steels
B880 Specification for General Requirements for Chemical
3.2.3 wire, n—cold finished only: round, square, octagon,
Check Analysis Limits for Nickel, Nickel Alloys and
hexagon, and shape wire, ⁄2 in. (12.7 mm) and under in
Cobalt Alloys
diameter or size. Cold-finished only: flat wire, ⁄16 in.
B889 Specification for Solid Hard-Drawn Aluminum Wire
(4.76 mm) to under ⁄8 in. (9.525 mm) in width, 0.010 in.
(0.254 mm) to under ⁄16 in. in thickness.
4. Ordering Information
This specification is under the jurisdiction of ASTM Committee B02 on
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee
4.1 It is the responsibility of the purchaser to specify all
B02.07 on Refined Nickel and Cobalt and Their Alloys.
requirements that are necessary for the safe and satisfactory
Current edition approved April 1, 2024. Published April 2024. Originally
approved in 1968. Last previous edition approved in 2018 as B473 – 07 (2018).
performance of material ordered under this specification.
DOI: 10.1520/B0473-24.
Examples of such requirements include, but are not limited to,
For ASME Boiler and Pressure Vessel Code applications see related Specifi-
the following:
cation SB-473 in Section II of that Code.
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’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
*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
B473 − 24
TABLE 1 Chemical Requirements
Composition, %
Element
UNS N08020
Carbon, max 0.07
Manganese, max 2.00
Phosphorus, max 0.045
Sulfur, max 0.035
Silicon, max 1.00
Nickel 32.00 to 38.00
Chromium 19.00 to 21.00
Molybdenum 2.00 to 3.00
Copper 3.00 to 4.00
Columbium (Nb) + tantalum 8 × carbon–1.00
Nitrogen .
A
Iron remainder
A
By difference.
A
TABLE 2 Mechanical Property Requirements
Diameter or
Tensile Strength, min Yield Strength, min
Elongation in 2 in. Reduction of area,
Condition Thickness,
(50.8 mm), min, % min, %
ksi MPa ksi MPa
in. (mm)
B
Annealed, hot finished or cold All 80 551 35 241 30.0 50.0
finished
Annealed, strain-hardened Up to 2 (50.8) incl 90 620 60 415 15.0 40.0
A
For wire only, tensile strength 90 ksi to 120.0 ksi (620 MPa to 830 MPa); no requirements on yield strength, elongation, and reduction of area.
B
Cold-finished shapes require only 15 %, minimum, elongation.
4.1.1 Quantity (weight or number of pieces), 7.2 Wire will be furnished only as annealed and cold
4.1.2 Name of material or UNS number, finished.
4.1.3 Form (bar or wire),
4.1.4 Dimensions,
8. Mechanical Properties
4.1.5 Condition,
8.1 The material shall conform to the applicable require-
4.1.6 Finish,
ments as to mechanical properties prescribed in Table 2.
4.1.7 ASTM designation and year of issue,
4.1.8 Inspection (15.1),
9. Dimensions and Permissible Variations
4.1.9 Supplementary requirements, if any, and
4.1.10 If possible, the intended end use. 9.1 Bar—Bars shall conform to the variations in dimensions
prescribed in Tables 3-11, inclusive, as applicable.
NOTE 1—A typical ordering description is as follows: 200 bars, UNS
N08020, 1 in. (25.4 mm) round by 10 ft to 14 ft (3.0 m to 3.6 m),
9.2 Wire—Wire shall conform to the permissible variations
centerless ground, Specification B473.
in dimensions prescribed in Tables 12-16, inclusive, as appli-
cable.
5. Materials and Manufacture
5.1 Heat Treatment—The product of UNS N08020 alloy
10. Workmanship, Finish, and Appearance
shall be furnished in the stabilized-annealed condition.
10.1 The product shall be uniform in quality and condition,
NOTE 2—The recommended annealing temperatures all followed by
smooth, commercially straight or flat, and free of injurious
quenching in water or rapidly cooling by other means are as follows:
imperfections.
1700 °F to 1850 °F (927 °C to 1010 °C) for UNS N08020.
11. Sampling
6. Chemical Composition
11.1 Lot:
6.1 The material shall conform to the requirements as to
11.1.1 A lot for chemical analysis shall consist of one heat.
chemical composition prescribed in Table 1.
11.1.2 A lot for mechanical properties shall consist of all
6.2 If a product (check) analysis is performed by the
material from the same heat, nominal diameter or thickness, of
purchaser, the material shall conform to the product (check)
each heat-treatment charge.
analysis variations prescribed in Specification B880.
11.2 Test Material Selection:
7. Condition
11.2.1 Chemical Analysis—Representative samples shall be
taken during pouring or subsequent processing.
7.1 Bars shall be furnished annealed and either hot finished
or cold finished. Strain-hardened material is available only as 11.2.1.1 Check analysis shall be wholly the responsibility of
cold finished. the purchaser.
B473 − 24
TABLE 3 Permissible Variations in Size of Hot-Rolled Round and Square Bars
A
Permissible Variations from Specified Size, in. (mm) Out-of-Round or
B
Out-of-Square,
Over Under
in. (mm)
1 5 C,D E E E
⁄4 (6.35) to ⁄16 (7.94), incl
C,D
5 7
Over ⁄16 (7.94) to ⁄16 (11.11), incl 0.006 (0.15) 0.006 (0.15) 0.009 (0.23)
C,D
7 5
Over ⁄16 (11.11) to ⁄8 (15.88), incl 0.007 (0.18) 0.007 (0.18) 0.010 (0.25)
5 7
Over ⁄8 (15.88) to ⁄8 (22.22), incl 0.008 (0.20) 0.008 (0.20) 0.012 (0.30)
Over ⁄8 (22.22) to 1 (25.40), incl 0.009 (0.23) 0.009 (0.23) 0.013 (0.33)
Over 1 (25.40) to 1 ⁄8 (28.58), incl 0.010 (0.25) 0.010 (0.25) 0.015 (0.38)
1 1
Over 1 ⁄8 (28.58) to 1 ⁄4 (31.75), incl 0.011 (0.28) 0.011 (0.28) 0.016 (0.41)
1 3
Over 1 ⁄4 (31.75) to 1 ⁄8 (34.92), incl 0.012 (0.30) 0.012 (0.30) 0.018 (0.46)
3 1
Over 1 ⁄8 (34.92) to 1 ⁄2 (38.10), incl 0.014 (0.36) 0.014 (0.36) 0.021 (0.53)
1 1 1
Over 1 ⁄2 (38.10) to 2 (50.80), incl ⁄64 (0.40) ⁄64 (0.40) 0.023 (0.58)
1 1
Over 2 (50.80) to 2 ⁄2 (63.50), incl ⁄32 (0.79) 0 0.023 (0.58)
1 1 3
Over 2 ⁄2 (63.50) to 3 ⁄2 (88.90), incl ⁄64 (1.19) 0 0.035 (0.89)
1 1 1
Over 3 ⁄2 (88.90) to 4 ⁄2 (114.30), incl ⁄16 (1.59) 0 0.046 (1.17)
1 1 5
Over 4 ⁄2 (114.30) to 5 ⁄2 (139.70), incl ⁄64 (1.98) 0 0.058 (1.47)
1 1 1
Over 5 ⁄2 (139.70) to 6 ⁄2 (165.10), incl ⁄8 (3.18) 0 0.070 (1.78)
1 5
Over 6 ⁄2 (165.10) to 8 (203.20), incl ⁄32 (3.97) 0 0.085 (2.18)
A
Out-of-round is the difference between the maximum and minimum diameters of the bar, measured at the same cross section.
B
Out-of-square section is the difference in the two dimensions at the same cross section of a square bar, each dimension being the distance between opposite faces.
C
1 5
Size tolerances have not been evolved for rounds in the size range of ⁄4 in. to ⁄16 in. (6.35 mm to 7.94 mm), inclusive. Size tolerances have not been evolved for round
1 5
sections in the size range of ⁄4 in. to approximately ⁄8 in. (6.35 mm to 15.88 mm) in diameter which are produced on rod mills in coils.
D
Variations in size of coiled product made on rod mills are greater than size tolerances for product made on bar mills.
E
Squares in this size are not produced as hot-rolled products.
TABLE 4 Permissible Variations in Size of Hot-Rolled Hexagonal and Octagonal Bars
Maximum Difference in
Permissible Variations from Specified Size, in. (mm)
Specified Sizes Measured
3 Measurements for
Between Opposite Sides,
Hexagons
in. (mm) Over Under
only, in. (mm)
1 1
⁄4 (6.35) to ⁄2 (12.70), incl 0.007 (0.18) 0.007 (0.18) 0.011 (0.28)
Over ⁄2 (12.70) to 1 (25.40), incl 0.010 (0.25) 0.010 (0.25) 0.015 (0.38)
Over 1 (25.40) to 1 ⁄2 (38.10), incl 0.021 (0.53) 0.021 (0.53) 0.025 (0.64)
1 1 1 1
Over 1 ⁄2 (38.10) to 2 (50.80), incl ⁄32 (0.79) ⁄32 (0.79) ⁄32 (0.79)
1 3 3 3
Over 2 (50.80) to 2 ⁄2 (63.50), incl ⁄64 (1.19) ⁄64 (1.19) ⁄64 (1.19)
1 1 1 1 1
Over 2 ⁄2 (63.50) to 3 ⁄2 (88.90), incl ⁄16 (1.59) ⁄16 (1.59) ⁄16 (1.59)
TABLE 5 Permissible Variations in Thickness and Width for Hot-Rolled Flat Bars
Permissible Variations in Thickness for Thicknesses Given, in. (mm)
1 1 1
Specified Width, in. (mm) ⁄8 (3.18) to ⁄2 (12.70), incl Over ⁄2 (12.70) to 1 (25.40), incl Over 1 (25.40) to 2 (50.80), incl
Over Under Over Under Over Under
To 1 (25.40), incl 0.008 (0.20) 0.008 (0.20) 0.010 (0.25) 0.010 (0.25) . .
Over 1 (25.40) to 2 (50.80), incl 0.012 (0.30) 0.012 (0.30) 0.015 (0.38) 0.015 (0.38) 0.031 (0.79) 0.031 (0.79)
Over 2 (50.80) to 4 (101.60), incl 0.015 (0.38) 0.015 (0.38) 0.020 (0.51) 0.020 (0.51) 0.031 (0.79) 0.031 (0.79)
Over 4 (101.60) to 6 (152.40), incl 0.015 (0.38) 0.015 (0.38) 0.020 (0.51) 0.020 (0.51) 0.031 (0.79) 0.031 (0.79)
Over 6 (152.40) to 8 (203.20), incl 0.016 (0.41) 0.016 (0.41) 0.025 (0.64) 0.025 (0.64) 0.031 (0.79) 0.031 (0.79)
Over 8 (203.20) to 10 (254.00), incl 0.021 (0.53) 0.021 (0.53) 0.031 (0.79) 0.031 (0.79) 0.031 (0.79) 0.031 (0.79)
Over 2 (50.80) to 4 (101.60), incl Over 4 (101.60) to 6 (152.40), incl Over 6 (152.40) to 8 (203.20), incl
Over Under Over Under Over Under
To 1 (25.40), incl . . . . . .
Over 1 (25.40) to 2 (50.80), incl . . . . . .
Over 2 (50.80) to 4 (101.60), incl 0.062 (1.57) 0.031 (0.79) . . . .
Over 4 (101.60) to 6 (152.40), incl 0.062 (1.57) 0.031 (0.79) 0.093 (2.36) 0.062 (1.57) . .
Over 6 (152.40) to 8 (203.20), incl 0.062 (1.57) 0.031 (0.79) 0.093 (2.36) 0.062 (1.57) 0.125 (3.18) 0.156 (3.96)
Over 8 (203.20) to 10 (154.00), incl 0.062 (1.57) 0.031 (0.79) 0.093 (2.36) 0.062 (1.57) 0.125 (3.18) 0.156 (3.96)
Permissible Variations in Width, in. (mm)
Specified Width, in. (mm)
Over Under
To 1 (25.40), incl 0.015 (0.38) 0.015 (0.38)
Over 1 (25.40) to 2 (50.80), incl 0.031 (0.79) 0.031 (0.79)
Over 2 (50.80) to 4 (101.60), incl 0.062 (1.57) 0.031 (0.79)
Over 4 (101.60) to 6 (152.40), incl 0.093 (2.36) 0.062 (1.57)
Over 6 (152.40) to 8 (203.20), incl 0.125 (3.18) 0.156 (3.96)
Over 8 (203.20) to 10 (254.00), incl 0.156 (3.96) 0.
...

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: B473 − 07 (Reapproved 2018) B473 − 24
Standard Specification for
UNS N08020, UNS N08024, and UNS N08026 Nickel Nickel-
Iron-Chromium-Molybdenum-Copper Alloy Bar and Wire
This standard is issued under the fixed designation B473; 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 Scope*
1.1 This specification covers UNS N08020, UNS N08026, and UNS N08024 N08020 bar and wire other than required for
reforging.
1.2 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.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to become familiar with all hazards including those identified in the appropriate Safety Data Sheet
(SDS) for this product/material as provided by the manufacturer, to establish appropriate safety, health, and environmental
practices, and determine the applicability of regulatory limitations prior to use.
1.4 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:
A262 Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels
B880 Specification for General Requirements for Chemical Check Analysis Limits for Nickel, Nickel Alloys and Cobalt Alloys
B889 Specification for Solid Hard-Drawn Aluminum Wire for Electrical Purposes (Withdrawn 2003)
E8/E8M Test Methods for Tension Testing of Metallic Materials
E1473 Test Methods for Chemical Analysis of Nickel, Cobalt, and High-Temperature Alloys
3. Terminology
3.1 Definitions:
3.1.1 Definitions for terms defined in Terminology B889 shall apply unless otherwise defined by the requirements of this
document.
3.2 Definitions of Terms Specific to This Standard:
This specification is under the jurisdiction of ASTM Committee B02 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.07 on Refined
Nickel and Cobalt and Their Alloys.
Current edition approved Nov. 1, 2018April 1, 2024. Published November 2018April 2024. Originally approved in 1968. Last previous edition approved in 20132018 as
B473 – 07 (2013).(2018). DOI: 10.1520/B0473-07R18.10.1520/B0473-24.
For ASME Boiler and Pressure Vessel Code applications see related Specification SB-473 in Section II of that Code.
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’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
*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
B473 − 24
3.2.1 The terms bar and wire as used in this specification are described as follows:
3.2.2 bars, n—hot-finished rounds, squares, octagons, and hexagons: ⁄4 in. (6.35 mm) and over in diameter or size. Hot-finished
1 1
flats: ⁄4 in. to 10 in. (254 mm), inclusive, in width, ⁄8 in. (3.175 mm) and over in thickness. Cold-finished rounds, squares,
1 3
octagons, hexagons, and shapes: over ⁄2 in. (12.7 mm) in diameter or size. Cold-finished flats: ⁄8 in. (9.525 mm) and over in width
(see Discussion (1)), ⁄8 in. and over in thickness (see Discussion (2)).
3.2.2.1 Discussion—
3 3
(1) Widths less than ⁄8 in. (9.525 mm) and thicknesses less than ⁄16 in. (4.75 mm) are generally described as flat wire.
3.2.2.2 Discussion—
1 3
(2) Thicknesses ⁄8 in. (3.175 mm) to under ⁄16 in. (4.75 mm) can be cold-rolled strip as well as bar.
3.2.3 wire, n—cold finished only: round, square, octagon, hexagon, and shape wire, ⁄2 in. (12.7 mm) and under in diameter or size.
3 3
Cold-finished only: flat wire, ⁄16 in. (4.76 mm) in. (4.76 mm) to under ⁄8 in. (9.525 mm) in width, 0.010 in. (0.254 mm) to under
⁄16 in. in thickness.
4. Ordering Information
4.1 It is the responsibility of the purchaser to specify all requirements that are necessary for the safe and satisfactory performance
of material ordered under this specification. Examples of such requirements include, but are not limited to, the following:
4.1.1 Quantity (weight or number of pieces),
4.1.2 Name of material or UNS number,
4.1.3 Form (bar or wire),
4.1.4 Dimensions,
4.1.5 Condition,
TABLE 1 Chemical Requirements
Composition, %
Element
UNS N08026
Carbon, max 0.03
Manganese, max 1.00
Phosphorus, max 0.03
Sulfur, max 0.03
Silicon, max 0.50
Nickel 33.00 to 37.20
Chromium 22.00 to 26.00
Molybdenum 5.00 to 6.70
Copper 2.00 to 4.00
Columbium (Nb) + tantalum .
Nitrogen 0.10 to 0.16
A
Iron remainder
TABLE 1 Chemical Requirements
Composition, %
Element
UNS N08020
Carbon, max 0.07
Manganese, max 2.00
Phosphorus, max 0.045
Sulfur, max 0.035
Silicon, max 1.00
Nickel 32.00 to 38.00
Chromium 19.00 to 21.00
Molybdenum 2.00 to 3.00
Copper 3.00 to 4.00
Columbium (Nb) + tantalum 8 × carbon–1.00
Nitrogen .
A
Iron remainder
A
By difference.
B473 − 24
A
TABLE 2 Mechanical Property Requirements
Diameter or
Tensile Strength, min Yield Strength, min
Elongation in 2 in. Reduction of area,
Condition Thickness,
(50.8 mm), min, % min, %
ksi MPa ksi MPa
in. (mm)
B
Annealed, hot finished or cold All 80 551 35 241 30.0 50.0
finished
B
Annealed, hot finished or cold All 80 551 35 241 30.0 50.0
finished
Annealed, strain-hardened Up to 2 (50.8) incl 90 620 60 415 15.0 40.0
A
For wire only, tensile strength 9090 ksi to 120.0 ksi (620 ksi (620 MPa to 830 MPa); no requirements on yield strength, elongation, and reduction of area.
B
Cold-finished shapes require only 15 %, minimum, elongation.
4.1.6 Finish,
4.1.7 ASTM designation and year of issue,
4.1.8 Inspection (15.1),
4.1.9 Supplementary requirements, if any, and
4.1.10 If possible, the intended end use.
NOTE 1—A typical ordering description is as follows: 200 bars, UNS N08020, 1 in. (25.4 mm) round by 10 to 14 ft (3.0 10 ft to 14 ft (3.0 m to 3.6 m),
centerless ground, Specification Specification B473.
5. Materials and Manufacture
5.1 Heat Treatment—The product of UNS N08020 alloy shall be furnished in the stabilized-annealed condition. The product of
UNS N08026 alloy shall be furnished in the solution-annealed condition. The product of UNS N08024 alloy shall be furnished
in the annealed condition.
NOTE 2—The recommended annealing temperatures all followed by quenching in water or rapidly cooling by other means are as follows: 1700 to 1850°F
(927 to 1010°C) for UNS N08020, 2050 to 2200°F (1121 to 1204°C) for UNS N08026, and 1925 to 1975°F (1052 to 1079°C) for UNS N08024.1700 °F
to 1850 °F (927 °C to 1010 °C) for UNS N08020.
6. Chemical Composition
6.1 The material shall conform to the requirements as to chemical composition prescribed in Table 1.
6.2 If a product (check) analysis is performed by the purchaser, the material shall conform to the product (check) analysis
variations prescribed in Specification B880.
7. Condition
7.1 Bars shall be furnished annealed and either hot finished or cold finished. Strain-hardened material is available only as cold
finished.
7.2 Wire will be furnished only as annealed and cold finished.
8. Mechanical Properties
8.1 The material shall conform to the applicable requirements as to mechanical properties prescribed in Table 2.
9. Dimensions and Permissible Variations
9.1 Bar—Bars shall conform to the variations in dimensions prescribed in Tables 3-11, inclusive, as applicable.
B473 − 24
TABLE 3 Permissible Variations in Size of Hot-Rolled Round and Square Bars
A
Out-of-Round or
Permissible Variations from Specified Size, in. (mm)
B
Out-of-Square,
Over Under
in. (mm)
C,D E E E
1 5
⁄4 (6.35) to ⁄16 (7.94), incl
C,D
5 7
Over ⁄16 (7.94) to ⁄16 (11.11), incl 0.006 (0.15) 0.006 (0.15) 0.009 (0.23)
C,D
7 5
Over ⁄16 (11.11) to ⁄8 (15.88), incl 0.007 (0.18) 0.007 (0.18) 0.010 (0.25)
5 7
Over ⁄8 (15.88) to ⁄8 (22.22), incl 0.008 (0.20) 0.008 (0.20) 0.012 (0.30)
Over ⁄8 (22.22) to 1 (25.40), incl 0.009 (0.23) 0.009 (0.23) 0.013 (0.33)
Over 1 (25.40) to 1 ⁄8 (28.58), incl 0.010 (0.25) 0.010 (0.25) 0.015 (0.38)
1 1
Over 1 ⁄8 (28.58) to 1 ⁄4 (31.75), incl 0.011 (0.28) 0.011 (0.28) 0.016 (0.41)
1 3
Over 1 ⁄4 (31.75) to 1 ⁄8 (34.92), incl 0.012 (0.30) 0.012 (0.30) 0.018 (0.46)
3 1
Over 1 ⁄8 (34.92) to 1 ⁄2 (38.10), incl 0.014 (0.36) 0.014 (0.36) 0.021 (0.53)
1 1 1
Over 1 ⁄2 (38.10) to 2 (50.80), incl ⁄64 (0.40) ⁄64 (0.40) 0.023 (0.58)
1 1
Over 2 (50.80) to 2 ⁄2 (63.50), incl ⁄32 (0.79) 0 0.023 (0.58)
1 1 3
Over 2 ⁄2 (63.50) to 3 ⁄2 (88.90), incl ⁄64 (1.19) 0 0.035 (0.89)
1 1 1
Over 3 ⁄2 (88.90) to 4 ⁄2 (114.30), incl ⁄16 (1.59) 0 0.046 (1.17)
1 1 5
Over 4 ⁄2 (114.30) to 5 ⁄2 (139.70), incl ⁄64 (1.98) 0 0.058 (1.47)
1 1 1
Over 5 ⁄2 (139.70) to 6 ⁄2 (165.10), incl ⁄8 (3.18) 0 0.070 (1.78)
1 5
Over 6 ⁄2 (165.10) to 8 (203.20), incl ⁄32 (3.97) 0 0.085 (2.18)
A
Out-of-round is the difference between the maximum and minimum diameters of the bar, measured at the same cross section.
B
Out-of-square section is the difference in the two dimensions at the same cross section of a square bar, each dimension being the distance between opposite faces.
C
1 5
Size tolerances have not been evolved for rounds in the size range of ⁄4 in. to ⁄16 in. (6.35(6.35 mm to 7.94 mm), inclusive. Size tolerances have not been evolved for
1 5
round sections in the size range of ⁄4 in. to approximately ⁄8 in. (6.35(6.35 mm to 15.88 mm) in diameter which are produced on rod mills in coils.
D
Variations in size of coiled product made on rod mills are greater than size tolerances for product made on bar mills.
E
Squares in this size are not produced as hot-rolled products.
TABLE 4 Permissible Variations in Size of Hot-Rolled Hexagonal and Octagonal Bars
Maximum Difference in
Permissible Variations from Specified Size, in. (mm)
Specified Sizes Measured
3 Measurements for
Between Opposite Sides,
Hexagons
in. (mm)
Over Under
only, in. (mm)
1 1
⁄4 (6.35) to ⁄2 (12.70), incl 0.007 (0.18) 0.007 (0.18) 0.011 (0.28)
Over ⁄2 (12.70) to 1 (25.40), incl 0.010 (0.25) 0.010 (0.25) 0.015 (0.38)
Over 1 (25.40) to 1 ⁄2 (38.10), incl 0.021 (0.53) 0.021 (0.53) 0.025 (0.64)
1 1 1 1
Over 1 ⁄2 (38.10) to 2 (50.80), incl ⁄32 (0.79) ⁄32 (0.79) ⁄32 (0.79)
1 3 3 3
Over 2 (50.80) to 2 ⁄2 (63.50), incl ⁄64 (1.19) ⁄64 (1.19) ⁄64 (1.19)
1 1 1 1 1
Over 2 ⁄2 (63.50) to 3 ⁄2 (88.90), incl ⁄16 (1.59) ⁄16 (1.59) ⁄16 (1.59)
TABLE 5 Permissible Variations in Thickness and Width for Hot-Rolled Flat Bars
Permissible Variations in Thickness for Thicknesses Given, in. (mm)
1 1 1
Specified Width, in. (mm) ⁄8 (3.18) to ⁄2 (12.70), incl Over ⁄2 (12.70) to 1 (25.40), incl Over 1 (25.40) to 2 (50.80), incl
Over Under Over Under Over Under
To 1 (25.40), incl 0.008 (0.20) 0.008 (0.20) 0.010 (0.25) 0.010 (0.25) . .
Over 1 (25.40) to 2 (50.80), incl 0.012 (0.30) 0.012 (0.30) 0.015 (0.38) 0.015 (0.38) 0.031 (0.79) 0.031 (0.79)
Over 2 (50.80) to 4 (101.60), incl 0.015 (0.38) 0.015 (0.38) 0.020 (0.51) 0.020 (0.51) 0.031 (0.79) 0.031 (0.79)
Over 4 (101.60) to 6 (152.40), incl 0.015 (0.38) 0.015 (0.38) 0.020 (0.51) 0.020 (0.51) 0.031 (0.79) 0.031 (0.79)
Over 6 (152.40) to 8 (203.20), incl 0.016 (0.41) 0.016 (0.41) 0.025 (0.64) 0.025 (0.64) 0.031 (0.79) 0.031 (0.79)
Over 8 (203.20) to 10 (254.00), incl 0.021 (0.53) 0.021 (0.53) 0.031 (0.79) 0.031 (0.79) 0.031 (0.79) 0.031 (0.79)
Over 2 (50.80) to 4 (101.60), incl Over 4 (101.60) to 6 (152.40), incl Over 6 (152.40) to 8 (203.20), incl
Over Under Over Under Over Under
To 1 (25.40), incl . . . . . .
Over 1 (25.40) to 2 (50.80), incl . . . . . .
Over 2 (50.80) to 4 (101.60), incl 0.062 (1.57) 0.031 (0.79) . . . .
Over 4 (101.60) to 6 (152.40), incl 0.062 (1.57) 0.031 (0.79) 0.093 (2.36) 0.062 (1.57) . .
Over 6 (152.40) to 8 (203.20), incl 0.062 (1.57) 0.031 (0.79) 0.093 (2.36) 0.062 (1.57) 0.125 (3.18) 0.156 (3.96)
Over 8 (203.20) to 10 (154.00), incl 0.062 (1.57) 0.031 (0.79) 0.093 (2.36) 0.062 (1.57) 0.125 (3.18) 0.156 (3.96)
Permissible Variations in Width, in. (mm)
Specified Width, in. (mm)
Over Under
To 1 (25.40), incl 0.015 (0.38) 0.015 (0.38)
Over 1 (25.40) to 2 (50.80), incl 0.031 (0.79) 0.031 (0.79)
Over 2 (50.80) to 4 (101.60), incl 0.062 (1.57) 0.031 (0.79)
Over 4 (101.60) to 6 (152.40), incl 0.093 (2.36) 0.062 (1.57)
Over 6 (152.40) to 8 (203.20), incl 0.125 (3.18) 0.156 (3.96)
Over 8 (203.20) to 10 (254.00), incl 0.156 (3.96) 0.187 (4.75)
9.2 Wire—Wire shall conform to the permissible variations in dimensions prescribed in Tables 12-16, inclusive, as applicable.
B473 − 24
TABLE 6 Permissible Variations in Size of Cold-Finished Round
Bars
Permissible Variations from Specified
A,B
Specified Size, in. (
...