Astm E8M-04

Designation: E 8M – 04
METRIC

Standard Test Methods for

Tension Testing of Metallic Materials [Metric]1
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
superscriptepsilon (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*
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, andreduction of area.

A 356/A356M Specification for Steel Castings, Carbon,
Low Alloy, and Stainless Steel, Heavy-Walled for Steam
Turbines
A 370 Test Methods and Definitions for Mechanical Testing
of Steel Products
B 557M Test Methods of Tension Testing Wrought and Cast
Aluminum- and Magnesium-Alloy Products [Metric]
E 4 Practices for Force Verification of Testing Machines
E 6 TerminologyRelating to Methods of Mechanical Testing
E 8 Test Methods for Tension Testing of Metallic Materials
E 29 Practice for Using Significant Digits in Test Data to
Determine Conformance with Specifications
E 83 Practice for Verification and Classification of Extensometers
E 345 Test Methods of Tension Testing of Metallic Foil
E 691 Practice for Conducting an Interlaboratory Study to
Determine thePrecision of a Test Method
E 1012 Practice for Verification of Specimen Alignment
Under Tensile Loading

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.
NOTE2—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 industrywide agreement to keep the pressing of the material to aspecific 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.

3. Terminology
3.1 Definitions—Thedefinitions of terms relating to tension
testing appearing in Terminology E 6 shall be considered as
applying to the terms used in these test methods of tension
testing. Additional terms being defined are as follows:
3.1.1 discontinuous yielding—in a uniaxial test, a hesitation
or fluctuation of force observed at the onset of plastic deformation, due to localized yielding. (The stress-strain curve neednot appear to be discontinuous.)
3.1.2 lower yield strength, LYS [FL−2]—in a uniaxial test,
the minimum stress recorded during discontinuous yielding,
ignoring transient effects.
3.1.3 upper yield strength, UYS [FL−2]—in a uniaxial test,
the first stress maximum (stress at first zero slope) associated
with discontinuous yielding.
3.1.4 yield point elongation, YPE—in a uniaxial test, thestrain (expressed in percent) separating the stress-strain curve’s
first point of zero slope from the point of transition from

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...