ASTM E8M-00a

Standard Test Methods for Tension Testing of Metallic Materials [Metric]

SCOPE
1.1 These test methods cover the tension testing of metallic materials in any form at room temperature, specifically, the methods of determination of yield strength, yield point elongation, tensile strength, elongation, and reduction of area.
Note 1—These test methods are the metric companion of Test Methods E 8. Committee E-28 was granted an exception in 1997 by the Committee on Standards to maintain E8 and E8M as separate companion standards rather than combining standards as recommended by the Form and Style manual.
Note 2—These metric test methods are essentially the same as those in Test Methods E 8, and are compatible in technical content except that gage lengths are required to be 5D for most round specimens rather than 4D as specified in Test Methods E 8. Test specimens made from powder metallurgy (P/M) materials are exempt from this requirement by industry-wide agreement to keep the pressing of the material to a specific projected area and density.
Note 3—Exceptions to the provisions of these test methods may need to be made in individual specifications or test methods for a particular material. For examples, see Test Methods and Definitions A 370 and Test Methods B 557M.
Note 4—Room temperature shall be considered to be 10 to 38°C unless otherwise specified.
1.2 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 and health practices and determine the applicability of regulatory limitations prior to use./p>

General Information

• Status: Historical
• Publication Date: 09-Oct-2001
• ICS: 77.040.10 - Mechanical testing of metals
• Technical Committee: E28 - Mechanical Testing
• Drafting Committee: E28.04 - Uniaxial Testing

Relations

• Replaced By: ASTM E8M-00b - Standard Test Methods for Tension Testing of Metallic Materials [Metric]
• Effective Date: 10-Oct-2001
• Referred By: ASTM F468M-06(2018) - Standard Specification for Nonferrous Bolts, Hex Cap Screws, and Studs for General Use (Metric)
• Effective Date: 10-Oct-2001
• Referred By: ASTM B811-13(2022)e1 - Standard Specification for Wrought Zirconium Alloy Seamless Tubes for Nuclear Reactor Fuel Cladding
• Effective Date: 10-Oct-2001
• Referred By: ASTM F2971-13(2021) - Standard Practice for Reporting Data for Test Specimens Prepared by Additive Manufacturing
• Effective Date: 10-Oct-2001
• Referred By: ASTM B557M-15(2023) - Standard Test Methods for Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy Products (Metric)
• Effective Date: 10-Oct-2001

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E 8M – 00a
METRIC
Standard Test Methods for
Tension Testing of Metallic Materials [Metric]
This standard is issued under the fixed designation E 8M; 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 (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope * Aluminum- and Magnesium-Alloy Products [Metric]
E 4 Practices for Force Verification of Testing Machines
1.1 These test methods cover the tension testing of metallic
E 6 Terminology Relating to Methods of Mechanical Test-
materials in any form at room temperature, specifically, the
ing
methods of determination of yield strength, yield point elon-
E 8 Test Methods for Tension Testing of Metallic Materials
gation, tensile strength, elongation, and reduction of area.
E 29 Practice for Using Significant Digits in Test Data to
NOTE 1—These test methods are the metric companion of Test Methods
Determine Conformance with Specifications
E 8. Committee E-28 was granted an exception in 1997 by the Committee
E 83 Practice for Verification and Classification of Exten-
on Standards to maintain E8 and E8M as separate companion standards
someters
rather than combining standards as recommended by the Form and Style
E 345 Test Methods of Tension Testing of Metallic Foil
manual.
NOTE 2—These metric test methods are essentially the same as those in E 691 Practice for Conducting an Interlaboratory Study to
Test Methods E 8, and are compatible in technical content except that gage
Determine the Precision of a Test Method
lengths are required to be 5D for most round specimens rather than 4D as
E 1012 Practice for Verification of Specimen Alignment
specified in Test Methods E 8. Test specimens made from powder
Under Tensile Loading
metallurgy (P/M) materials are exempt from this requirement by industry-
wide agreement to keep the pressing of the material to a specific projected
3. Terminology
area and density.
3.1 Definitions—The definitions of terms relating to tension
NOTE 3—Exceptions to the provisions of these test methods may need
to be made in individual specifications or test methods for a particular testing appearing in Terminology E 6 shall be considered as
material. For examples, see Test Methods and Definitions A 370 and Test
applying to the terms used in these test methods of tension
Methods B 557M.
testing. Additional terms being defined are as follows:
NOTE 4—Room temperature shall be considered to be 10 to 38°C unless
3.1.1 discontinuous yielding—a hesitation or fluctuation of
otherwise specified.
force observed at the onset of plastic deformation, due to
1.2 This standard does not purport to address all of the
localized yielding. (The stress-strain curve need not appear to
safety concerns, if any, associated with its use. It is the
be discontinuous.)
−2
responsibility of the user of this standard to establish appro-
3.1.2 lower yield strength, LYS [FL ]—the minimum stress
priate safety and health practices and determine the applica-
recorded during discontinuous yielding, ignoring transient
bility of regulatory limitations prior to use.
effects.
−2
3.1.3 upper yield strength, UYS [FL ]—the first stress
2. Referenced Documents
maximum (stress at first zero slope) associated with discon-
2.1 ASTM Standards:
tinuous yielding.
A 356/A356M Specification for Steel Castings, Carbon,
3.1.4 yield point elongation, YPE—the strain (expressed in
Low Alloy, and Stainless Steel, Heavy-Walled for Steam
percent) separating the stress-strain curve’s first point of zero
Turbines
slope from the point of transition from discontinuous yielding
A 370 Test Methods and Definitions for Mechanical Testing
to uniform strain hardening. If the transition occurs over a
of Steel Products
range of strain, the YPE end point is the intersection between
B 557M Test Methods of Tension Testing Wrought and Cast
(a) a horizontal line drawn tangent to the curve at the last zero
slope and ( b) a line drawn tangent to the strain hardening
portion of the stress-strain curve at the point of inflection. If
These test methods are under the jurisdiction of ASTM Committee E-28 on
Mechanical Testing and are the direct responsibility of Subcommittee E28.04 on
there is no point at or near the onset of yielding at which the
Uniaxial Testing.
Current edition approved May 10, 2000. Published August 2000. Originally
published as E 8M – 84. Last previous edition E 8M – 99.
Annual Book of ASTM Standards, Vol 02.02.
Annual Book of ASTM Standards, Vol 01.02.
Annual Book of ASTM Standards, Vol 03.01.
Annual Book of ASTM Standards, Vol 01.03.
Annual Book of ASTM Standards, Vol 14.02.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
E8M
slope reaches zero, the material has 0 % YPE. 5.2.3 Grips for Threaded and Shouldered Specimens and
Brittle Materials—A schematic diagram of a gripping device
4. Significance and Use
for threaded-end specimens is shown in Fig. 3, while Fig. 4
4.1 Tension tests provide information on the strength and
shows a device for gripping specimens with shouldered ends.
ductility of materials under uniaxial tensile stresses. This Both of these gripping devices should be attached to the heads
information may be useful in comparisons of materials, alloy
of the testing machine through properly lubricated spherical-
development, quality control, and design under certain circum- seated bearings. The distance between spherical bearings
stances.
should be as great as feasible.
4.2 The results of tension tests of specimens machined to 5.2.4 Grips for Sheet Materials—The self-adjusting grips
standardized dimensions from selected portions of a part or
shown in Fig. 5 have proved satisfactory for testing sheet
material may not totally represent the strength and ductility materials that cannot be tested satisfactorily in the usual type of
properties of the entire end product or its in-service behavior in
wedge grips.
different environments. 5.2.5 Grips for Wire—Grips of either the wedge or snub-
4.3 These test methods are considered satisfactory for ac-
bing types as shown in Fig. 5 and Fig. 6 or flat wedge grips
ceptance testing of commercial shipments. The test methods may be used.
have been used extensively in the trade for this purpose.
5.3 Dimension-Measuring Devices—Micrometers and other
devices used for measuring linear dimensions shall be accurate
5. Apparatus
and precise to at least one half the smallest unit to which the
5.1 Testing Machines—Machines used for tension testing
individual dimension is required to be measured.
shall conform to the requirements of Practices E 4. The forces
5.4 Extensometers—Extensometers used in tension testing
used in determining tensile strength and yield strength shall be
shall conform to the requirements of Practice E 83 for the
within the verified force application range of the testing
classifications specified by the procedure section of this test
machine as defined in Practices E 4.
method. Extensometers shall be used and verified to include
5.2 Gripping Devices:
strains corresponding to the yield strength and elongation at
5.2.1 General—Various types of gripping devices may be
fracture (if determined).
used to transmit the measured force applied by the testing
5.4.1 Extensometers with gage lengths equal to or shorter
machine to the test specimens. To ensure axial tensile stress
than the nominal gage length of the specimen (dimensions
within the gage length, the axis of the test specimen should
shown as “G-Gage Length” in the accompanying figures) may
coincide with the center line of the heads of the testing
be used to determine the yield behavior. For specimens without
machine. Any departure from this requirement may introduce
a reduced section (for example, full cross sectional area
bending stresses that are not included in the usual stress
specimens of wire, rod, or bar), the extensometer gage length
computation (force divided by cross-sectional area).
for the determination of yield behavior shall not exceed 80 %
of the distance between grips. For measuring elongation at
NOTE 5—The effect of this eccentric force application may be illus-
fracture with an appropriate extensometer the gage length of
trated by calculating the bending moment and stress thus added. For a
standard 12.5-mm diameter specimen, the stress increase is 1.5 % for each the extensometer shall be equal to the nominal gage length
0.025 mm of eccentricity. This error increases to about 2.5 %/0.025 mm
required for the specimen being tested.
for a 9-mm diameter specimen and to about 3.2 %/0.025 mm for a 6-mm
6. Test Specimens
diameter specimen.
NOTE 6—Alignment methods are given in Practice E 1012.
6.1 General:
5.2.2 Wedge Grips—Testing machines usually are equipped 6.1.1 Specimen Size—Test specimens shall be either sub-
with wedge grips. These wedge grips generally furnish a stantially full size or machined, as prescribed in the product
satisfactory means of gripping long specimens of ductile metal specifications for the material being tested.
and flat plate test specimens such as those shown in Fig. 1. If, 6.1.2 Location—Unless otherwise specified, the axis of the
however, for any reason, one grip of a pair advances farther test specimen shall be located within the parent material as
than the other as the grips tighten, an undesirable bending follows:
stress may be introduced. When liners are used behind the 6.1.2.1 At the center for products 40 mm or less in thick-
wedges, they must be of the same thickness and their faces ness, diameter, or distance between flats.
must be flat and parallel. For best results, the wedges should be 6.1.2.2 Midway from the center to the surface for products
supported over their entire lengths by the heads of the testing over 40 mm in thickness, diameter, or distance between flats.
machine. This requires that liners of several thicknesses be 6.1.3 Specimen Machining—Improperly prepared test
available to cover the range of specimen thickness. For proper specimens often are the reason for unsatisfactory and incorrect
gripping, it is desirable that the entire length of the serrated test results. It is important, therefore, that care be exercised in
face of each wedge be in contact with the specimen. Proper the preparation of specimens, particularly in the machining, to
alignment of wedge grips and liners is illustrated in Fig. 2. For maximize precision and minimize bias in test results.
short specimens and for specimens of many materials, it is 6.1.3.1 The reduced sections of prepared specimens should
generally necessary to use machined test specimens and to use be free of cold work, notches, chatter marks, grooves, gouges,
a special means of gripping to ensure that the specimens, when burrs, rough surfaces or edges, overheating, or any other
under load, shall be as nearly as possible in uniformly condition which may deleteriously affect the properties to be
distributed pure axial tension (see 5.2.3, 5.2.4, and 5.2.5). measured.
E8M
Dimensions, mm
Standard Specimens Subsize Specimen
Nominal Width
Plate-Type Sheet-Type
6mm
40 mm 12.5 mm
G— Gage length (Note 1 and Note 2) 200.0 6 0.2 50.0 6 0.1 25.0 6 0.1
W— Width (Note 3 and Note 4) 40.0 6 2.0 12.5 6 0.2 6.0 6 0.1
T— Thickness (Note 5) thickness of material
R— Radius of fillet, min (Note 6) 25 12.5 6
L— Overall length, min (Note 2 and Note 7) 450 200 100
A— Length of reduced section, min 225 57 32
B— Length of grip section, min (Note 8) 75 50 30
C— Width of grip section, approximate (Note 4 and Note 9) 50 20 10
NOTE 1—For the 40-mm wide specimen, punch marks for measuring elongation after fracture shall be made on the flat or on the edge of the specimen
and within the reduced section. Either a set of nine or more punch marks 25 mm apart, or one or more pairs of punch marks 200 mm apart, may be used.
NOTE 2—When elongation measurements of 40-mm wide specimens are not required, a minimum length of reduced section (A) of 75 mm may be used
with all other dimensions similar to the plate-type specimen.
NOTE 3—For the three sizes of specimens, the ends of the reduced section shall not differ in width by more than 0.10, 0.05 or 0.02 mm, respectively.
Also, there may be a gradual decrease in width from the ends to the center, but the width at each end shall not be more than 1 % larger than the width
at the center.
NOTE 4—For each of the three sizes of 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.
NOTE 5—The dimension T is the thickness of the test specimen as provided for in the applicable material specifications. Minimum thickness of 40-mm
wide specimens shall be 5 mm. Maximum thickness of 12.5-mm and 6-mm wide specimens shall be 19 mm and 6 mm, respectively.
NOTE 6—For the 40-mm wide specimen, a 13-mm minimum radius at the ends of the reduced section is permitted for steel specimens under 690 MPa
in tensile strength when a profile cutter is used to machine the reduced section.
NOTE 7—To aid in obtaining axial force application during testing of 6-mm wide specimens, the overall length should be as large as the material will
permit, up to 200 mm.
NOTE 8—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 10 mm, longer grips and correspondingly longer
grip sections of the specimen may be necessary to prevent failure in the grip section.
NOTE 9—For the three sizes of specimens, the ends of the specimen shall be symmetrical in width with the center line of the reduced section within
2.5, 0.25, and 0.13 mm, respectively. However, for referee testing and when required by product specifications, the ends of the 12.5-mm wide specimen
shall be symmetrical within 0.2 mm.
NOTE 10—For each specimen type, the radii of all fillets shall be equal to each other within a tolerance of 1.25 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 2.5 mm.
NOTE 11—Specimens with sides paral
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