ASTM E290-22

Standard Test Methods for Bend Testing of Material for Ductility

SIGNIFICANCE AND USE
5.1 Bend tests for ductility provide a simple way to evaluate the quality of materials by their ability to resist cracking or other surface irregularities during one continuous bend. No reversal of the bend force shall be employed when conducting these tests.  
5.2 The type of bend test used determines the location of the forces and constraints on the bent portion of the specimen, ranging from no direct contact to continuous contact.  
5.3 The test can terminate at a given angle of bend over a specified radius of bend or continue until the specimen legs are in contact. The angle of bend can be measured while the specimen is under the bending force (usually when the semi-guided bend test is employed), or after removal of the force as when performing a free-bend test. Product requirements for the material being tested determine the method used.  
5.4 Materials with an as-fabricated cross section of rectangular, round, hexagonal, or similar defined shape can be tested in full section to evaluate their bend properties by using the procedures outlined in these test methods, in which case relative width and thickness requirements do not apply.
SCOPE
1.1 These test methods cover bend testing for ductility of materials. Included in the procedures are four conditions of constraint on the bent portion of the specimen; a guided-bend test using a mandrel or plunger of defined dimensions to force the mid-length of the specimen between two supports separated by a defined space; a semi-guided bend test in which the specimen is bent, while in contact with a mandrel, through a specified angle of bend or to a specified inside radius of bend (r) measured while under the bending force; a free-bend test in which the ends of the specimen are brought toward each other, but in which no transverse force is applied to the bend itself and there is no contact of the concave inside surface of the bend with other material; a bend-and-flatten test, in which a transverse force is applied to the bend such that the legs make contact with each other over the length of the specimen.  
1.2 After bending, the convex surface of the bend is examined for evidence of a crack or surface irregularities. If the specimen fractures, the material has failed the test. When complete fracture does not occur, the criterion for failure is the number and size of cracks or surface irregularities visible to the unaided eye occurring on the convex surface of the specimen after bending, as specified by the product specification. Any cracks within one thickness of the edge of the specimen are not considered a bend test failure. Cracks occurring in the corners of the bent portion shall not be considered significant unless they exceed the size specified for corner cracks in the product specification.  
1.3 The values stated in SI units are to be regarded as standard. Inch-pound values given in parentheses were used in establishing test parameters and are for information only.  
1.4 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.  
1.5 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: 14-Jun-2022
• ICS: 77.040.10 - Mechanical testing of metals
• Technical Committee: E28 - Mechanical Testing
• Drafting Committee: E28.02 - Ductility and Formability

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: E290 − 22
Standard Test Methods for
1
Bend Testing of Material for Ductility
This standard is issued under the fixed designation E290; 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* priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.1 These test methods cover bend testing for ductility of
1.5 This international standard was developed in accor-
materials. Included in the procedures are four conditions of
dance with internationally recognized principles on standard-
constraint on the bent portion of the specimen; a guided-bend
ization established in the Decision on Principles for the
test using a mandrel or plunger of defined dimensions to force
Development of International Standards, Guides and Recom-
themid-lengthofthespecimenbetweentwosupportsseparated
mendations issued by the World Trade Organization Technical
by a defined space; a semi-guided bend test in which the
Barriers to Trade (TBT) Committee.
specimen is bent, while in contact with a mandrel, through a
specified angle of bend or to a specified inside radius of bend
2. Referenced Documents
(r) measured while under the bending force; a free-bend test in
2
2.1 ASTM Standards:
which the ends of the specimen are brought toward each other,
E6 Terminology Relating to Methods of Mechanical Testing
but in which no transverse force is applied to the bend itself
E8/E8M Test Methods for Tension Testing of Metallic Ma-
and there is no contact of the concave inside surface of the
terials
bend with other material; a bend-and-flatten test, in which a
E190 Test Method for Guided Bend Test for Ductility of
transverse force is applied to the bend such that the legs make
Welds
contact with each other over the length of the specimen.
1.2 After bending, the convex surface of the bend is 3. Terminology
examined for evidence of a crack or surface irregularities. If
3.1 Definitions—RefertoTerminologyE6forthedefinitions
the specimen fractures, the material has failed the test. When
of bend test, ductility and springback.
complete fracture does not occur, the criterion for failure is the
3.1.1 guided bend, n—the bend obtained by using a mandrel
numberandsizeofcracksorsurfaceirregularitiesvisibletothe
to guide and force the portion of the specimen being bent
unaided eye occurring on the convex surface of the specimen
between two faces of a die.
after bending, as specified by the product specification. Any
3.2 Definitions of Terms Specific to This Standard:
cracks within one thickness of the edge of the specimen are not
3.2.1 angle of bend, n—the change in the angle between the
considered a bend test failure. Cracks occurring in the corners
two legs of the specimen during a bend test, measured before
of the bent portion shall not be considered significant unless
release of the bending forces, unless otherwise specified.
they exceed the size specified for corner cracks in the product
3.2.2 bend-and-flatten bend, n—the bend obtained by com-
specification.
pressing the legs of a 180° bend between platens until the legs
1.3 The values stated in SI units are to be regarded as
of the bend contact.
standard. Inch-pound values given in parentheses were used in
3.2.3 crack, n—a nominally two-dimensional defect caused
establishing test parameters and are for information only.
by the bend test that extends primarily from the surface of the
1.4 This standard does not purport to address all of the
test specimen to its interior.
safety concerns, if any, associated with its use. It is the
3.2.3.1 Discussion—Different disciplines characterize and
responsibility of the user of this standard to establish appro-
describe cracks using different, specific terminology. The
terminology of a specification that cites E290 shall always be
followed instead of any crack terminology defined here.
1
This test method is under the jurisdiction of ASTM Committee E28 on
Mechanical Testing and is the direct responsibility of Subcommittee E28.02 on
2
Ductility and Formability. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved June 15, 2022. Published September 2022. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1966. Last previous edition approved in 2014 as E290 – 14. DOI: Standards vo
...

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: E290 − 14 E290 − 22
Standard Test Methods for
1
Bend Testing of Material for Ductility
This standard is issued under the fixed designation E290; 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*
1.1 These test methods cover bend testing for ductility of materials. Included in the procedures are four conditions of constraint
on the bent portion of the specimen; a guided-bend test using a mandrel or plunger of defined dimensions to force the mid-length
of the specimen between two supports separated by a defined space; a semi-guided bend test in which the specimen is bent, while
in contact with a mandrel, through a specified angle of bend or to a specified inside radius (r) of curvature, bend (r) measured while
under the bending force; a free-bend test in which the ends of the specimen are brought toward each other, but in which no
transverse force is applied to the bend itself and there is no contact of the concave inside surface of the bend with other material;
a bend and flatten bend-and-flatten test, in which a transverse force is applied to the bend such that the legs make contact with each
other over the length of the specimen.
1.2 After bending, the convex surface of the bend is examined for evidence of a crack or surface irregularities. If the specimen
fractures, the material has failed the test. When complete fracture does not occur, the criterion for failure is the number and size
of cracks or surface irregularities visible to the unaided eye occurring on the convex surface of the specimen after bending, as
specified by the product standard.specification. Any cracks within one thickness of the edge of the specimen are not considered
a bend test failure. Cracks occurring in the corners of the bent portion shall not be considered significant unless they exceed the
size specified for corner cracks in the product standard.specification.
1.3 The values stated in SI units are to be regarded as standard. Inch-pound values given in parentheses were used in establishing
test parameters and are for information only.
1.4 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 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
2.1 ASTM Standards:
E6 Terminology Relating to Methods of Mechanical Testing
1
This test method is under the jurisdiction of ASTM Committee E28 on Mechanical Testing and is the direct responsibility of Subcommittee E28.02 on Ductility and
Formability.
Current edition approved May 1, 2014June 15, 2022. Published September 2014September 2022. Originally approved in 1966. Last previous edition approved in 20132014
as E290 – 13.E290 – 14. DOI: 10.1520/E0290-14.10.1520/E0290-22.
2
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.
*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
1

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E290 − 22
E8/E8M Test Methods for Tension Testing of Metallic Materials
E18 Test Methods for Rockwell Hardness of Metallic Materials
E190 Test Method for Guided Bend Test for Ductility of Welds
3. Terminology
3.1 Definitions—Refer to Terminology E6 for the definitions of bend test, ductility and springback.
3.1.1 guided bend, n—the bend obtained by using a mandrel to guide and force the portion of the specimen being bent between
two faces of a die.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 angle of bend, n—the
...