Aheg

Designation: E 8 – 00

American Association State
Highway and Transportation Officials Standard
AASHTO No.: T68

Standard Test Methods for

Tension Testing of Metallic Materials1
This standard is issued under the fixed designation E 8; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision. A numberin 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.

E 4 Practices for Force Verification of Testing Machines5
E 6 Terminology Relating to Methods of Mechanical Testing5
E 8M Test Methods for Tension Testing ofMetallic Materials [Metric]5
E 29 Practice for Using Significant Digits in Test Data to
Determine Conformance with Specifications6
E 83 Practice for Verification and Classification of Extensometers5
E 345 Test Methods of Tension Testing of Metallic Foil5
E 691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method6
E 1012 Practice for Verification of SpecimenAlignment
Under Tensile Loading5

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, and reduction of area.
NOTE 1—A complete metric companion to Test Methods E 8 has been
developed—; therefore, no metric equivalentsare shown in these test
methods. Committee E28 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—Gage lengths in these test methods are required to be 4D for
most round specimens. Test specimens made from powder metallurgy
(P/M) materialsare 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 557.
NOTE 4—Room temperature shallbe considered to be 50 to 100°F
unless otherwise specified.

3. Terminology
3.1 Definitions—The definitions 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—a hesitation or fluctuation of
force observed at theonset of plastic deformation, due to
localized yielding. (The stress-strain curve need not appear to
be discontinuous.)
3.1.2 lower yield strength, LYS [FL−2]—the minimum stress
recorded during discontinuous yielding, ignoring transient
effects.
3.1.3 upper yield strength, UYS [FL−2]— the first stress
maximum (stress at first zero slope) associated with discontinuous yielding.
3.1.4 yieldpoint elongation, YPE—the strain (expressed in
percent) separating the stress-strain curve’s first point of zero
slope from the point of transition from discontinuous yielding
to uniform strain hardening. If the transition occurs over a
range of strain, the YPE end point is the intersection between
(a) a horizontal line drawn tangent to the curve at the last zero
slope and ( b) a line drawntangent to the strain hardening
portion of the stress-strain curve at the point of inflection. If
there is no point at or near the onset of yielding at which the
slope reaches zero, the material has 0 % YPE.

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...