ASTM B557M-15(2023)

Standard Test Methods for Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy Products (Metric)

SIGNIFICANCE AND USE
4.1 Tension tests provide information on the strength and ductility of materials under uniaxial tensile stresses. This information may be useful in comparisons of materials, alloy development, quality control, and design under certain circumstances.  
4.2 The results of tension tests of specimens machined to standardized dimensions from selected portions of a part or material may not totally represent the strength and ductility properties of the entire end product or its in-service behavior in different environments.  
4.3 These test methods are considered satisfactory for acceptance testing of commercial shipments and have been used extensively in the trade for this purpose.
SCOPE
1.1 These test methods cover the tension testing of wrought and cast aluminum- and magnesium-alloy products, with the exception of aluminum foil,2 and are derived from Test Methods E8M, which cover the tension testing of all metallic materials.
Note 1: These metric test methods are the equivalents of those in Test Methods B557, and are compatible in technical content except for the requirement of longer gage lengths for round specimens.
Note 2: Foil is sheet metal less than 0.20 mm thick. There is an overlap in the thickness range 0.15 mm to 0.20 mm defined for foil and sheet. Sheet products in this thickness range are supplied to sheet product specifications and foil products in this thickness range are supplied to foil product specifications. Exceptions to the provisions of these test methods may need to be made in individual specifications or test methods for a particular material.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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 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-2023
• ICS: 77.150.10 - Aluminium products
• ICS: 77.150.20 - Magnesium products
• Technical Committee: B07 - Light Metals and Alloys
• Drafting Committee: B07.05 - Testing

Relations

• Refers: ASTM E345-24 - Standard Test Methods of Tension Testing of Metallic Foil
• Effective Date: 01-Jan-2024
• Refers: ASTM E345-16 - Standard Test Methods of Tension Testing of Metallic Foil
• Effective Date: 15-Jul-2016
• Refers: ASTM E4-14 - Standard Practices for Force Verification of Testing Machines
• Effective Date: 01-Jun-2014
• Refers: ASTM E345-93(2013)e1 - Standard Test Methods of Tension Testing of Metallic Foil
• Effective Date: 01-Nov-2013
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM E1012-12 - Standard Practice for Verification of Testing Frame and Specimen Alignment Under Tensile and Compressive Axial Force Application
• Effective Date: 01-Jun-2012
• Refers: ASTM E1012-12e1 - Standard Practice for Verification of Testing Frame and Specimen Alignment Under Tensile and Compressive Axial Force Application
• Effective Date: 01-Jun-2012
• Refers: ASTM E691-11 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2011
• Refers: ASTM B209-10 - Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate
• Effective Date: 01-Nov-2010
• Refers: ASTM E83-10a - Standard Practice for Verification and Classification of Extensometer Systems
• Effective Date: 01-Jun-2010
• Refers: ASTM E4-10 - Standard Practices for Force Verification of Testing Machines
• Effective Date: 01-Jun-2010
• Refers: ASTM E83-10 - Standard Practice for Verification and Classification of Extensometer Systems
• Effective Date: 01-Jan-2010
• Refers: ASTM E4-09a - Standard Practices for Force Verification of Testing Machines
• Effective Date: 01-Nov-2009
• Refers: ASTM E6-09be1 - Standard Terminology Relating to Methods of Mechanical Testing
• Effective Date: 15-May-2009
• Refers: ASTM E6-09b - Standard Terminology Relating to Methods of Mechanical Testing
• Effective Date: 15-May-2009

Overview

ASTM B557M-15(2023) is the internationally recognized standard detailing the test methods for tension testing wrought and cast aluminum- and magnesium-alloy products using metric units. Developed by ASTM International and approved by agencies such as the U.S. Department of Defense, this standard provides a uniform methodology for evaluating the strength and ductility of these light metal alloys under uniaxial tensile stresses. Its robust procedures underpin material comparisons, quality control processes, alloy development, and acceptance testing for commercial shipments in the aluminum and magnesium alloy industries.

Key Topics

• Test Scope and Applicability

  • Covers tension testing for wrought and cast aluminum and magnesium alloys, excluding aluminum foil (defined as sheet metal thinner than 0.20 mm).
  • Based on established mechanical testing standards (e.g., ASTM E8M), adapted for metric units and alloy-specific requirements.

• Significance and Use

  • Tension testing yields critical data on material strength and ductility.
  • Results support material selection, quality control, alloy development, and comparative analysis.
  • Widely utilized for acceptance testing in commercial transactions.

• Specimen Preparation and Testing

  • Specifies specimen dimensions and types (rectangular, round, pin-loaded, etc.).
  • Details requirements for gripping devices (wedge, threaded, snubbing grips) and testing machine calibration and precision (per ASTM E4 and E83).
  • Provides for accurate measurement of specimen cross-section and gage length for reliable elongation and fracture assessment.

• Procedure and Safety

  • Includes steps for proper preparation of specimens and testing apparatus.
  • Urges adherence to safety, health, and environmental practices as per user protocols.

Applications

ASTM B557M is essential for:

• Quality Control:
  Manufacturers employ these test methods to verify consistency and compliance in aluminum- and magnesium-alloy products, ensuring batch-to-batch reliability.

• Material Comparison and Design:
  Engineers and designers use the test data to compare different alloy properties, select materials for specific applications, and anticipate in-service performance.

• Commercial Acceptance Testing:
  The standardized methodology supports fair and repeatable testing of supplied products, fostering trust and clarity in supplier-customer relationships.

• Research and Alloy Development:
  Material scientists utilize these methods for alloy optimization, exploring new compositions and heat treatments with measurable strength and ductility benchmarks.

• Regulatory and Compliance Testing:
  Conforms to World Trade Organization (WTO) principles for international standards, facilitating cross-border trade of metal products and compliance with global procurement requirements.

Related Standards

For comprehensive mechanical testing and specification of nonferrous metals, refer to the following ASTM and related standards:

• ASTM B209 – Specification for Aluminum and Aluminum-Alloy Sheet and Plate (Metric).
• ASTM E4 – Practices for Force Calibration and Verification of Testing Machines.
• ASTM E6 – Terminology Relating to Methods of Mechanical Testing.
• ASTM E8M – Test Methods for Tension Testing of Metallic Materials [Metric].
• ASTM E83 – Practice for Verification and Classification of Extensometer Systems.
• ASTM E691 – Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method.
• ASTM E1012 – Practice for Verification of Testing Frame and Specimen Alignment Under Tensile and Compressive Axial Force Application.
• ASTM E345 – Test Methods of Tension Testing of Metallic Foil.

Keywords: ASTM B557M, tension testing, aluminum alloy, magnesium alloy, mechanical testing, tensile strength, ductility, quality control, acceptance testing, international standards

By adhering to ASTM B557M-15(2023), organizations in the metals industry can ensure reliable, consistent, and internationally recognized tension testing results for wrought and cast aluminum- and magnesium-alloy products.

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: B557M − 15 (Reapproved 2023)
Standard Test Methods for
Tension Testing Wrought and Cast Aluminum- and
Magnesium-Alloy Products (Metric)
This standard is issued under the fixed designation B557M; 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 2. Referenced Documents
1.1 These test methods cover the tension testing of wrought 2.1 ASTM Standards:
and cast aluminum- and magnesium-alloy products, with the B209 Specification for Aluminum and Aluminum-Alloy
exception of aluminum foil, and are derived from Test Sheet and Plate (Metric) B0209_B0209M
Methods E8M, which cover the tension testing of all metallic E4 Practices for Force Calibration and Verification of Test-
materials. ing Machines
E6 Terminology Relating to Methods of Mechanical Testing
NOTE 1—These metric test methods are the equivalents of those in Test
E8M Test Methods for Tension Testing of Metallic Materials
Methods B557, and are compatible in technical content except for the
[Metric] (Withdrawn 2008)
requirement of longer gage lengths for round specimens.
NOTE 2—Foil is sheet metal less than 0.20 mm thick. There is an
E29 Practice for Using Significant Digits in Test Data to
overlap in the thickness range 0.15 mm to 0.20 mm defined for foil and
Determine Conformance with Specifications
sheet. Sheet products in this thickness range are supplied to sheet product
E83 Practice for Verification and Classification of Exten-
specifications and foil products in this thickness range are supplied to foil
someter Systems
product specifications. Exceptions to the provisions of these test methods
E345 Test Methods of Tension Testing of Metallic Foil
may need to be made in individual specifications or test methods for a
particular material.
E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.2 The values stated in SI units are to be regarded as
E1012 Practice for Verification of Testing Frame and Speci-
standard. No other units of measurement are included in this
men Alignment Under Tensile and Compressive Axial
standard.
Force Application
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Terminology
responsibility of the user of this standard to establish appro-
3.1 The definitions of terms relating to tension testing
priate safety, health, and environmental practices and deter-
appearing in Terminology E6 shall be considered as applying
mine the applicability of regulatory limitations prior to use.
to the terms used in these test methods.
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard-
4. Significance and Use
ization established in the Decision on Principles for the
4.1 Tension tests provide information on the strength and
Development of International Standards, Guides and Recom-
ductility of materials under uniaxial tensile stresses. This
mendations issued by the World Trade Organization Technical
information may be useful in comparisons of materials, alloy
Barriers to Trade (TBT) Committee.
development, quality control, and design under certain circum-
stances.
These test methods are under the jurisdiction of ASTM Committee B07 on
Light Metals and Alloys and are the direct responsibility of Subcommittee B07.05 For referenced ASTM standards, visit the ASTM website, www.astm.org, or
on Testing. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Current edition approved April 1, 2023. Published April 2023. Originally Standards volume information, refer to the standard’s Document Summary page on
approved in 1976. Last previous edition approved in 2015 as B557M – 15. DOI: the ASTM website.
10.1520/B0557M-15R23. The last approved version of this historical standard is referenced on
For test methods of tension testing of aluminum foil, see Test Methods E345. 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
B557M − 15 (2023)
4.2 The results of tension tests of specimens machined to specimens and to use a special means of gripping to ensure that
standardized dimensions from selected portions of a part or the specimens, when under load, shall be as nearly as possible
material may not totally represent the strength and ductility in uniformly distributed pure axial tension (see 5.2.3 – 5.2.5).
properties of the entire end product or its in-service behavior in 5.2.3 Grips for Threaded and Shouldered Specimens—A
different environments. schematic diagram of a gripping device for threaded-end
specimens is shown in Fig. 2, while Fig. 3 shows a device for
4.3 These test methods are considered satisfactory for ac-
gripping specimens with shouldered ends. Both of these
ceptance testing of commercial shipments and have been used
gripping devices should be attached to the heads of the testing
extensively in the trade for this purpose.
machine through properly lubricated spherical-seated bearings.
The distance between spherical bearings should be as large as
5. Apparatus
feasible.
5.1 Testing Machines—Machines used for tension testing
5.2.4 Grips for Sheet Materials—The self-adjusting grips
shall conform to the requirements of Practices E4. The forces
shown in Fig. 4 have proved satisfactory for testing sheet
used in determining tensile strength and yield strength shall be
materials that cannot be tested satisfactorily in the usual type of
within the verified force application range of the testing
wedge grips.
machine as defined in Practices E4.
5.2.5 Grips for Wire—Grips of either the wedge or snubbing
5.2 Gripping Devices:
types as shown in Figs. 4 and 5 or flat wedge grips may be
5.2.1 General—Various types of gripping devices may be
used.
used to transmit the measured load applied by the testing
5.3 Dimension-Measuring Devices—Micrometers and other
machine to the test specimens. To ensure axial tensile stress
devices used for measuring linear dimensions shall be accurate
within the gage length, the axis of the test specimen must
and precise to at least one half the smallest unit to which the
coincide with the centerline of the heads of the testing
individual dimension is required to be measured.
machine. Any departure from this requirement may introduce
5.4 Extensometers—Extensometers used in tensile testing
bending stresses that are not included in the usual stress
shall conform to the requirements of Practice E83 for the
computation (load divided by cross-sectional area).
NOTE 3—The effect of this eccentric loading may be illustrated by
calculating the bending moment and stress thus added. For a standard
12.50 mm diameter specimen, the stress increase is 1.5 percentage points
for each 0.025 mm of eccentricity. This error increases to about 2.3
percentage points/0.025 mm for a 9 mm diameter specimen and to 3.25
percentage points /0.025 mm for a 6 mm diameter specimen.
NOTE 4—Alignment methods are given in Practice E1012.
5.2.2 Wedge Grips—Testing machines usually are equipped
with wedge grips. These wedge grips generally furnish a
satisfactory means of gripping long bars of ductile metal. If,
however, for any reason, one grip of a pair advances farther
than the other as the grips tighten, an undesirable bending
stress may be introduced. When liners are used behind the
wedges, they must be of the same thickness and their faces
must be flat and parallel. For best results, the wedges should be
supported over their entire length by the heads of the testing
machine. This requires that liners of several thicknesses be
available to cover the range of specimen thickness. For proper
gripping, it is desirable that the entire length of the serrated
face of each wedge be in contact with the specimen. Proper
alignment of wedge grips and liners is illustrated in Fig. 1. For
short specimens it is generally necessary to use machined test
FIG. 1 Wedge Grips with Liners for Flat Specimens FIG. 2 Gripping Device for Threaded-End Specimens
B557M − 15 (2023)
FIG. 5 Snubbing Device for Testing Wire
the strains corresponding to the yield strength and elongation at
fracture (if determined).
5.4.1 Extensometers with gage lengths equal to or shorter
than the nominal gage length of the specimen (dimension
shown as “G-gage Length” in the accompanying figures) may
be used to determine the yield behavior. For measuring
elongation at fracture with an appropriate extensometer, the
gage length of the extensometer shall be equal to the nominal
FIG. 3 Gripping Device for Shouldered-End Specimens
gage length required for the specimen being tested.
6. Test Specimen
6.1 General:
6.1.1 Test specimens shall be of the full section of the
material whenever practical. Otherwise, machined specimens
of rectangular or round cross section shall be used.
6.1.2 Improperly prepared test specimens often are the
reason for unsatisfactory and incorrect test results. It is
important, therefore, that care be exercised in the preparation
of specimens, particularly in the machining, to ensure the
desired precision and bias in test results.
6.1.3 The cross-sectional area of the specimen should be
smallest at the center of the reduced section to ensure fracture
within the gage length. For this reason, a small taper is
permitted in the reduced section of each of the specimens
described in the following sections.
6.1.4 Rectangular specimens shall be 12.50 mm wide in
accordance with Fig. 6 or Fig. 7 (for tubular products), and
shall be of the full thickness of the material when practical.
When necessary, 6.00 mm wide subsize specimens as shown in
Fig. 6 may be used, but elongation values from such specimens
are not applicable to specification requirements.
6.1.4.1 Pin ends as shown in Fig. 8 may be used. In order to
avoid buckling in tests of thin and high-strength materials, it
may be necessary to use stiffening plates at the grip ends.
6.1.5 Round specimens shall be the standard 12.50 mm
diameter specimen in Fig. 9, except when the dimensions of the
product make this impossible. In such cases, small-size speci-
mens proportional to the standard specimen shown in Fig. 9
FIG. 4 Gripping Devices for Sheet and Wire Specimens
may be used. Unless otherwise specified in the product
specification, the selection of round tensile specimens shall be
classifications specified by the procedure section of these test as specified in Table 1. Unless permitted by the product
methods. Extensometers shall be used and verified to include specification, the diameter of the reduced section of the
B557M − 15 (2023)
Dimensions, mm
Standard Specimen Sheet-Type
Subsize Specimen 6 mm Wide
12.5 mm Wide
G—gage length 50.0 ± 0.1 25.0 ± 0.1
W—Width (Note 1 and Note 2) 12.5 ± 0.2 6.0 ± 0.1
T—Thickness (Note 3) thickness of material thickness of material
R—Radius of fillet, min 12.5 6
L—Overall length, min (Note 4) 200 100
A—Length of reduced section, min 57 32
B—Length of grip section, min (Note 5) 50 30
C—Width of grip section, approximate (Note 2 and Note 6) 20 10
NOTE 1—The ends of the reduced section shall not differ in width by more than 0.06 mm for the 50.00 mm gage length specimen or 0.025 mm for
the 25.00 mm gage length specimen. There may be a gradual taper in width from the ends of the reduced section to the center, but the width at each end
shall not be more than 1 % greater than the width at the center.
NOTE 2—For each of the specimens, narrower widths (W and C) may be used when necessary. In such cases the width of the reduced section should
be as large as the width of the material being tested permits: however, unless stated specifically, the requirements for elongation in a product specification
shall not apply when these narrower specimens are used. If the width of the material is less than W, the sides may be parallel throughout the length of
the specimen.
NOTE 3—The dimension T is the thickness of the test specimen as stated in the applicable material specifications. Maximum nominal thicknesses of
12.5 mm and 6 mm wide specimens shall be 12.5 mm and 6 mm, respectively.
NOTE 4—To aid in obtaining axial loading during testing of 6 mm wide specimens, the overall length should be as large as the material will permit,
up to 200 mm.
NOTE 5—It is desirable, if possible, to make the length of the grip section large enough to allow the specimen to extend into the grips a distance equal
to two thirds or more of the length of the grips. If the thickness of 12.5 mm wide specimens is over 9 mm, longer grips and correspondingly longer grip
sections of the specimens may be necessary to prevent failure in the grip section.
NOTE 6—The grip-end centerline of the 12.5 mm wide and 6 mm wide specimens shall coincide with the centerline of the reduced section within 0.2
mm and 0.1 mm, respectively.
FIG. 6 Rectangular Tension Test Specimens
Dimensions, mm
G—gage length 50.00 ± 0.10
W—Width (Note 1) 12.50 ± 0.25
T—Measured thickness of specimen Note 2
R—Radius of fillet, min 12.5
A—Length of reduced section, min 57
B—Length of grip section, min (Note 3) 75
C—Width of grip section, approximate (Note 4) 20
NOTE 1—The ends of the reduced section shall not differ in width by more than 0.06 mm. There may be a gradual taper in width from the ends of
the reduced section to the center, but the width at each end shall not be more than 1 % greater than the width at the center.
NOTE 2—The dimension T is the thickness of the tubular section as provided for in the applicable material specifications.
NOTE 3—It is desirable, if possible, to make the length of the grip section great enough to allow the specimen to extend into the grips a distance equal
to two thirds or more of the length of the grips.
NOTE 4—The grip-end centerline of the specimen shall coincide with the centerline of the reduced section within 1.00 mm.
NOTE 5—For circular segments, the cross-sectional area shall be calculated using the formula shown in 7.2.3.
NOTE 6—The radii of all fillets shall be equal to each other within a tolerance of 1.00 mm, and the centers of curvature of the two fillets at a particular
end shall be located across from each other (on a line perpendicular to the centerline) within a tolerance of 2.00 mm.
FIG. 7 Longitudinal Tension Specimens for Large-Diameter Tubular Products
B557M − 15 (2023)
Dimensions, mm
G—gage length 50.00 ± 0.10
W—Width (Note 1) 12.50 ± 0.25
T—Thickness, max (Note 2) 12.5
R—Radius of fillet, min (Note 3) 13
L—Overall length, min 200
A—Length of reduced section, min 57
B—Length of grip section, min 50
C—Width of grip section, approximate 50
D—Diameter of hole for pin, min (Note 4) 13
E—Edge distance from pin, approximate 40
F—Distance from hole to fillet, min 15
NOTE 1—The ends of the reduced section shall not differ in width by more than 0.06 mm. There may be a gradual taper in width from the ends of
the reduced section to the center, but the width at each end shall not be more than 1 % greater than the width at the center.
NOTE 2—The dimension T is the thickness of the test specimen as stated in the applicable product specifications.
NOTE 3—For some materials, a fillet radius R larger than 13 mm may be needed.
NOTE 4—Holes must be on centerline of reduced section, within 60.05 mm.
NOTE 5—Variations of dimensions C, D, E, F, and L may be used that will permit failure within the gage length.
FIG. 8 Pin-Loaded Tension Test Specimen with 50 mm gage Length
Dimensions, mm
Nominal Diameter Standard Specimen Small-Size Specimens Proportional to Standard
12.5 9 6 4
G—gage length 62.50 ± 0.10 45.00 ± 0.09 30.00 ± 0.06 20.00 ± 0.04
D—Diameter (Note 1) 12.50 ± 0.25 9.00 ± 0.10 6.00 ± 0.10 4.00 ± 0.05
R— Radius of fillet, min 9 8 6 4
A—Length of reduced section, min (Note 2) 75 54 36 24
NOTE 1—The reduced section may have a gradual taper from the ends toward the center, with the ends not more than 1 % larger in diameter than the
center (controlling dimension).
NOTE 2—If desired, the length of the reduced section may be increased to accommodate an extensometer of any convenient gage length. Reference
marks for the measurement of elongation should, nevertheless, be spaced at the indicated gage length.
NOTE 3—The gage length and fillets shall be as shown, but the ends may be of any form to fit the holders of the testing machine in such a way that
the load shall be axial (see Fig. 10). If the ends are held in wedge grips it is desirable, if possible, to make the length of the grip section great enough
to allow the specimen to extend into the grips a distance equal to two thirds or more of the length of the grips.
NOTE 4—On the round specimens in Figs. 9 and 10, the gage lengths are equal to five times the nominal diameter. In some product specifications other
specimens may be provided for, but unless the 5-to-1 ratio is maintained within dimensional tolerances, the elongation values may not be comparable
with those obtained from the standard test specimen.
NOTE 5—The use of specimens smaller than 6.00 mm diameter shall be restricted to cases when the material to be tested is of insufficient size to obtain
larger specimens or when all parties agree to their use for acceptance testing. Smaller specimens require suitable equipment and greater skill in both
machining and testing.
FIG. 9 Standard 12.5 mm Round Tension Test Specimen with 62.5 mm gage Length and Examples of Small-Size Specimens Propor-
tional to the Standard Specimen
B557M − 15 (2023)
TABLE 1 Guidelines for Selecting Round Tensile Specimens
6.1.7 While tensile strengths and yield strengths can prop-
Minimum Material erly be compared with results derived from test specimens of
Specified Material
Section Thickness Specimen
Thickness, mm
various dimensions, elongation values may vary with specimen
Length or Diameter, mm
size and type. Therefore, elongation values should be obtained
Over Through
Width, mm
with specimens of the type from which the published tensile
6.30 9.50 40 4
9.50 12.50 60 6
properties were established.
12.50 16.00 80 9
6.2 Type, Direction, and Location in Wrought Products—
16.00 120 12.5
This paragraph and subparagraphs provide the standard re-
quirements for the testing of wrought products for the purpose
of quality control and lot release testing. Additions or excep-
tions to these requirements may need to be made in individual
smallest specimen used shall not be less than 4 mm for wrought
specifications for a particular material or product.
products and 6 mm for cast products.
NOTE 5—These requirements also do not preclude the use of these test
6.1.5.1 The shape of the ends of the specimen outside of the
methods for purposes other than quality control as desired for research,
gage length shall be suitable to the material and of a shape to
material evaluation, or other purpose utilizing other test locations, test
fit the holders or grips of the testing machine so that the loads
directions, and test specimen sizes. In these cases, the general require-
are applied axially. Fig. 10 shows specimens with various types
ments in 6.1 should be followed for specimen type and the requirements
of ends that have given satisfactory results. in Sections 5 and 7 shall be followed for test apparatus, testing, and
analysis.
6.1.6 Special care is required in the manufacture and testing
of smaller specimens because the effects of machining (for 6.2.1 Sheet and Plate:
example, the amount of end load applied and the amount of 6.2.1.1 Tension test specimens for non-heat-treatable alumi-
heat generated) and testing (for example, eccentricity and gage num alloy sheet and plate shall be taken so that the specimen
marking) variables are greater upon them than upon larger axis is parallel to the direction of rolling (longitudinal speci-
specimens. Therefore, the largest practical specimen shall mens).
always be used. With some types of materials, notably castings,
6.2.1.2 Tension test specimens for heat-treatable aluminum
the result of tests of small specimens may be more variable due alloy sheet (specified thickness less than 6.35 mm) shall be
to the increasing significance of variations in metallic structure
taken so that the specimen axis is perpendicular to the direction
or the character of the surfaces. Low values derived from small of rolling (long transverse) for product widths 230 mm and
specimens should be carefully evaluated in accordance with greater, and in the longitudinal direction for widths less than
8.1 to be certain that the results are valid. 230 mm.
Dimensions, mm
Specimen 1 Specimen 2 Specimen 3 Specimen 4 Specimen 5
G—gage length 62.50 ± 0.10 62.50 ± 0.10 62.50 ± 0.10 62.50 ± 0.10 62.50 ± 0.10
D—Diameter (Note 1) 12.50 ± 0.25 12.50 ± 0.25 12.50 ± 0.25 12.50 ± 0.25 12.50 ± 0.25
R—Radius of fillet, min 9 9 9 9 9
A—Length of reduced section 75, min 75, min 100, approximately 75, min 75, min
L—Overall length, approximate 145 155 140 140 255
B—Length of end section (Note 2) 35, approximately 25, approximately 20, approximately 15, approximately 75, min
C—Diameter of end section 20 20 20 22 20
E—Length of shoulder and fillet 15 20 15
section, approximate
F—Diameter of shoulder 15 15 15
NOTE 1—The reduced section may have a gradual taper from the ends toward the center with the ends not more than 1 % larger in diameter than the
center.
NOTE 2—On Specimen 5 it is desirable, if possible, to make the length of the grip section great enough to allow the specimen to extend into the grips
a distance equal to two thirds or more of the length of the grips.
FIG. 10 Various Types of Ends for Standard Round Tension Test Specimen
B557M − 15 (2023)
6.2.1.3 Tension test specimens for heat-treatable aluminum 6.2.3.2 Specimens shall be taken in the longitudinal direc-
alloy plate (specified thickness of 6.35 mm and greater) shall tion from the predominant section of the extrusion profile. The
be taken in the long transverse direction and, when specified, in specimens shall be taken from a location that most nearly
the longitudinal and short transverse (specimen axis perpen- satisfies the intent of Table 2.
dicular to the surface of the rolled product) directions. Long 6.2.4 Tube and Pipe—Specimens shall be taken in the
transverse and longitudinal tensile test specimens are taken longitudinal direction.
midway between the two plate surfaces for plate having a 6.2.4.1 For all tube (Note 8), particularly sizes 25 mm and
specified thickness of 12.5 mm through 40 mm, and midway under in nominal outside diameter, and frequently for larger
between the center and surface of plate for plate having a sizes, except as limited by the testing equipment, it is standard
specified thickness over 40 mm. Short transverse tensile practice to use tension test specimens of full-size tubular
specimens are taken so that the midpoint of the gage section sections. Snug-fitting metal plugs shall be inserted far enough
coincides with the plate mid-thickness plane. Short transverse into the ends of such tubular specimens to permit the testing
testing, when specified, is applicable to plate having a specified machine jaws to grip the specimens properly. The plugs shall
thickness of 40 mm and greater. not extend into that part of the specimen on which the
elongation is measured. Fig. 11 shows a suitable form of plug,
NOTE 6—ASTM Specification B209 lists thick plate products for which
the location of the plugs in the specimen, and the location of
short transverse tensile tests are required.
the specimen in the grips of the testing machine.
NOTE 7—In some cases, customer requirements may call for tensile
testing in the short transverse direction for plate with a specified thickness
NOTE 8—The term “tube” is used to indicate tubular products in
less than 40 mm. In these cases, the specimen geometry, preparation,
general, and includes pipe, tube, and tubing.
sampling requirements, and test procedure shall be agreed upon by the
supplier and customer. The precautionary information in 6.1.6 and 6.1.7
6.2.4.2 When it is not practical to test full-section
should be considered in these cases. Because of potentially higher scatter
specimens, 12.50 mm wide specimens in accordance with Fig.
and specimen size effects, data from such tests should not be combined
7 taken as in Fig. 12 shall be used if practical. Otherwise, round
with short transverse tensile test data from products having a specified
specimens in accordance with 6.1.5 shall be taken from the
thickness of 40 mm and greater which were tested using the specimen
geometry provided in Fig. 9. center of wall thicknesses through 40 mm; for thicknesses over
40 mm, they shall be taken midway from center of thickness to
6.2.1.4 Tension test specimens for aluminum alloy sheet and
surface. If specimens of the type shown in Fig. 7 are used and
plate less than 12.5 mm thick shall be the standard rectangular
curved grip faces are not available, it is acceptable to flatten
specimen. For plate thickness 12.5 mm and greater, the
(without heating) the grip ends of the test specimen. The gage
standard 12.5 mm round specimen, or a smaller round speci-
length area shall not be deformed.
men proportional to it, shall be used. Material less than 20 mm
6.2.5 Die Forgings—Round specimens shall be used for
in width is tested in full section when the standard 12.5 mm
section thicknesses over 12.50 mm. Either subsize round or
round specimen, or smaller round specimen proportional to it,
rectangular specimens may be used for section thickness from
cannot be used.
8.0 mm to 12.5 mm. Rectangular specimens shall be used for
6.2.1.5 Tension test specimens for magnesium alloys shall
section thicknesses less than 8.0 mm. The direction of the
be taken parallel to the direction of rolling.
specimens shall be in the longitudinal grain direction, unless
6.2.2 Wire, Rod, and Bar:
specimens in the other directions are required. For aluminum
6.2.2.1 Full-section specimens shall be used when practical.
die forgings, the longitudinal grain direction is defined as
It is permissible to reduce the section slightly throughout the
orientations parallel, within 615°, to the predominate grain
test section in order to ensure fracture within the gage length.
Otherwise, round specimens shall be used, except that for
rectangles of 12.50 mm and less in thickness, rectangular
specimens of the full thickness may be used.
6.2.2.2 Specimens shall be taken in the longitudinal direc-
tion from the locations specified in Table 2.
6.2.3 Extrusion Profiles:
6.2.3.1 Round specimens shall be used whenever it is not
practical to use full-section specimens, except that rectangular
specimens may be used for extrusion profiles less than
12.50 mm thick.
TABLE 2 Location of Axis of Specimen in Rod, Bar, and
Extrusion Profiles
Location of Axis of Specimen with
Section Diameter, Respect to Thickness (T) and Width (W)
Thickness or of Bar and Shapes or Diameter
NOTE 1—The diameter of the plug shall have a slight taper from the line
Width, mm (D) of Rod
limiting the testing machine jaws to the curved section.
Thickness Width Diameter
FIG. 11 Metal Plugs for Testing Tubular Specimens, Proper Loca-
Up through 40.0, incl T/2 W/2 D/2
Over 40.0 T/4 W/4 D/4 tion of Plugs in Specimen and of Specimen in Heads of Testing
Machine
B557M − 15 (2023)
6.3.1 Test specimens shall be separately cast or, if called for
by product specification or customer requirements, machined
from the casting itself.
6.3.2 Cast Test Specimens—Cast test specimens shall be
prepared in accordance with the appropriate product specifica-
tion.
6.3.3 Specimens Machined from Castings:
6.3.3.1 Round specimens in accordance with Fig. 9 shall be
used for section thicknesses over 12.50 mm.
6.3.3.2 Either small-size round specimens proportional to
the standard specimen in Fig. 9 or rectangular specimens in
NOTE 1—The edges of the specimen shall be cut parallel to each other.
accordance with Fig. 6 may be used for section thicknesses
FIG. 12 Location from Which Longitudinal Tension Test Speci-
from 8.0 mm to 12.50 mm, except as limited by 6.1.3.
mens Are to Be Cut from Large-Diameter Tube
6.3.3.3 Rectangular specimens in accordance with Fig. 6
shall be used for section thickness less than 8.0 mm.
flow. The long transverse grain direction is defined as
6.3.3.4 All test specimens must have a machined finish of
perpendicular, within 615°, to the longitudinal (predominate)
1.6 μm RMS (1.4 μm AA) or smoother.
grain direction and parallel, within 615°, to the parting plane.
6.4 Specimen for Die Castings—For testing die castings the
(Both conditions must be met.) The short transverse grain
test specimen shown in Fig. 13 shall be used unless otherwise
direction is defined as perpendicular, within 615°, to the
provided in the product specifications.
longitudinal (predominate) grain direction and perpendicular,
6.5 Specimens for Powdered Metals—For testing powdered
within 615°, to the parting plane. Specimens shall be taken
metals the test specimens shown in Fig. 14 and Fig. 15 shall be
from the center of the predominant or thickest part of the
used, unless otherwise provided in the product specifications.
forging from which a coupon can be obtained, from a prolon-
gation of the forging, or from separately forged coupons from
7. Procedure
the same stock and representative of the forging.
6.2.6 Hand Forgings—Round specimens shall be used. 7.1 Preparation of the Test Machine—Upon startup, or
They shall be taken in the long-transverse direction, and when following a prolonged period of machine inactivity, exercise or
specified, in the longitudinal and short-transverse directions. A warm up the test machine to normal operating temperatures to
longitudinal specimen shall be taken so that its axis coincides minimize errors that may result from transient conditions.
with the longitudinal centerline of the forging. A long-
7.2 Measurement of Dimensions of Test Specimens:
transverse or short-transverse specimen shall be taken so that
7.2.1 To determine the cross-sectional area of a tension test
the midpoint of its axis lies on the longitudinal centerline of the
specimen, measure the dimensions of the cross section at the
forging. Each specimen shall be so chosen that the distance
center of the reduced section. However, for referee testing of
from the midpoint of its axis to the end of the forging is at least
specimens under 5.0 mm in their least dimension, measure the
half the thickness of the forging.
dimensions where the least cross-sectional area is found.
6.3 Type of Specimen from Sand and Permanent Mold Measure and record the cross-sectional dimensions of tension
Castings: test specimens 5.0 mm and over to the nearest 0.025 mm; the
Dimensions, mm
G—gage length 60.00 ± 0.10
D—Diameter (see Note) 6.00 ± 0.10
R—Radius of fillet, min 75
A—Length of reduced section, min 75
L—Overall length, min 250
B—Distance between grips, min 125
C—Diameter of end section, approximate 10
NOTE 1—The reduced section may have a gradual taper from the ends toward the center, with the ends not more than 0.10 mm larger in diameter
than the center.
FIG. 13 Standard Tension Test Specimen for Die Castings
B557M − 15 (2023)
Approximate Pressing Area = v 650 mm
Dimensions Specified except G, are Those of the Die.
Dimensions, mm
G—gage length 25.40 ± 0.10
D—Width at center 5.72 ± 0.03
W—Width at end of reduced section 5.97 ± 0.03
T—Compact to this thickness 5 to 6.5
R—Radius of fillet 25
A—Half-length of reduced section 16
B—Grip length 81
L—Overall length 90
C—Width of grip section 8.71 ± 0.03
F—Half width of grip section 4.36 ± 0.03
E—End radius 4.36 ± 0.03
FIG. 14 Standard Tension Test Specimen for Powdered Metal
Products—Flat
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