ASTM E855-08

Standard Test Methods for Bend Testing of Metallic Flat Materials for Spring Applications Involving Static Loading

SIGNIFICANCE AND USE
Measurements of bending strength and modulus of elasticity in bending should be made for materials whose principal stressing mode is bending. For many materials, the tensile and compressive moduli are somewhat different. Since the bending modulus is a combination of the tensile and compressive moduli, it is often different from each of them.
Precise measurements of the modulus of elasticity in bending and bending strength require due regard for numerous variables that may affect their determination. These include (1) characteristics such as specimen orientation with respect to the rolling direction, grain size, residual stresses, previous strain history, dimensions and specimen preparation, orientation of deformed grains relative to the direction of the normal stress; and (2) test conditions, such as tem-
perature, temperature variations, condition of the test equipment and adherence to the recommended test procedure.
SCOPE
1.1 This standard describes three test methods for determining the modulus of elasticity in bending and the bending strength of metallic strips or sheets intended for the use in flat springs:
1.1.1 Test Method A—a cantilever beam,
1.1.2 Test Method B—a three-point loaded beam (that is, a beam resting on two supports and centrally loaded), and
1.1.3 Test Method C—a four-point loaded beam (that is, a beam resting on two supports and loaded at two points equally spaced from each support).
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered 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 and health practices and determine the applicability of regulatory limitations prior to use.  
6.1 This test method covers the determination of the modulus of elasticity in bending and the offset yield strength in bending of flat metallic strips or sheets for spring applications. The test procedure involves measurements of the applied moment and the corresponding angle of deflection of a cantilever beam. The thickness range covered is 0.015 to 0.130 in. (0.38 to 3.30 mm). This test method is not applicable for nonlinear elastic materials.  
15.1 These test methods cover the determination of the modulus of elasticity in bending and the bending proof strength of flat metallic strips or sheets for spring applications. The test methods consist of deflection tests of a simple beam configuration subjected to either three- or four-point symmetrical loading. The thickness range covered is 0.010 to 0.050 in. (0.25 to 1.3 mm).  
Note 3—Thickness ranges outside of those specified may be agreed upon between suppliers and users.

General Information

• Status: Historical
• Publication Date: 30-Nov-2008
• ICS: 21.160 - Springs
• Technical Committee: E28 - Mechanical Testing
• Drafting Committee: E28.02 - Ductility and Formability

Relations

• Replaces: ASTM E855-90(2000) - Standard Test Methods for Bend Testing of Metallic Flat Materials for Spring Applications Involving Static Loading
• Effective Date: 01-Dec-2008

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E855 − 08
StandardTest Methods for
Bend Testing of Metallic Flat Materials for Spring
1
Applications Involving Static Loading
This standard is issued under the fixed designation E855; 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.
1. Scope E177 Practice for Use of the Terms Precision and Bias in
2 ASTM Test Methods
1.1 This standard describes three test methods for deter-
E691 Practice for Conducting an Interlaboratory Study to
mining the modulus of elasticity in bending and the bending
Determine the Precision of a Test Method
strength of metallic strips or sheets intended for the use in flat
springs:
3. Terminology
1.1.1 Test Method A—a cantilever beam,
1.1.2 Test Method B—a three-point loaded beam (that is, a 3.1 Definitions of Terms Specific to This Standard:
beam resting on two supports and centrally loaded), and
3.1.1 In addition to the terms in Terminology E6, the
1.1.3 Test Method C—a four-point loaded beam (that is, a
following descriptions of terms apply in connection with these
beam resting on two supports and loaded at two points equally
test methods for determining bend properties:
spaced from each support).
3.1.2 bend properties—those properties of a material that
1.2 The values stated in inch-pound units are to be regarded are associated with elastic and inelastic behavior when a
bending force is applied, or that involve the relationship
as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only between bending stress and strain.
and are not considered standard. −2
3.1.3 bending stress at outer fiber (FL )—the nominal
1.3 This standard does not purport to address all of the
stressintheouterfibersofabeamresultingfromapplicationof
safety concerns, if any, associated with its use. It is the
a bending load.
responsibility of the user of this standard to establish appro-
−2
3.1.4 elastic limit in bending (FL )—the greatest bending
priate safety and health practices and determine the applica-
stress that a material is capable of sustaining without perma-
bility of regulatory limitations prior to use.
nent strain remaining after complete release of the bending
moment.
2. Referenced Documents
−2
3.1.5 modulus of elasticity in bending (FL )—the ratio of
2.1 The following documents of the issue in effect on date
bending stress to corresponding strain below the elastic limit in
of use of these test methods form a part of these test methods
bending.
to the extent referenced herein:
3
3.1.6 span length (L)—the distance between supports.
2.2 ASTM Standards:
E4 Practices for Force Verification of Testing Machines
3.1.7 uniform bending moment (FL)—a bending moment
E6 Terminology Relating to Methods of Mechanical Testing
that produces a uniform strain at the outer fibers throughout the
E111 Test Method for Young’s Modulus, Tangent Modulus,
gage length of the specimen.
and Chord Modulus
−2
3.1.8 bending proof strength (FL )—the nominal stress in
the outer fibers of a beam that results in a specific permanent
1 strain in the outer fibers upon unloading.
These test methods are under the jurisdiction of ASTM Committee E28 on
Mechanical Testing and are the direct responsibility of Subcommittee E28.02 on
−2
3.1.9 cyclic bending yield strength (FL )—the maximum
Ductility and Formability.
nominalstressinuniformcyclicbendingresultingfromagiven
Current edition approved Dec. 1, 2008. Published January 2009. Originally
approved in 1981. Last previous edition approved in 2005 as E855 – 05. DOI:
plastic deformation in the outer fibers of a beam.
10.1520/E0855-08.
−2
2
3.1.10 offset yield strength in bending (FL )—thenominal
Method D, which appeared in the last previous edition, was dropped because of
the unavailability of commercial testing equipment.
stress in the outer fibers of a beam in bending at which a
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
specified limiting deviation from proportionality of bending
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
stress to bending strain is exhibited.The deviation is expressed
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. in terms of strain.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E855 − 08
4. Significance and Use 8. Significance and Use
8.1 This test method may be used for obtaining values of
4.1 Measurements of bending strength and modulus of
offset yield strength
...

This document is not anASTM standard and is intended only to provide the user of anASTM 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:E855–90(Reapproved 2000) Designation:E855–08
Standard Test Methods for
Bend Testing of Metallic Flat Materials for Spring
1
Applications Involving Static Loading
This standard is issued under the fixed designation E855; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
2
1.1 This standard describes three test methods for determining the modulus of elasticity in bending and the bending strength
of metallic strips or sheets intended for the use in flat springs:
1.1.1 Test Method A—a cantilever beam,
1.1.2 Test Method B—a three-point loaded beam (that is, a beam resting on two supports and centrally loaded), and
1.1.3 Test Method C—afour-pointloadedbeam(thatis,abeamrestingontwosupportsandloadedattwopointsequallyspaced
from each support).
1.2Values stated in inch-pound units are to be regarded as the standard. SI units are provided for information only.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered 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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 The following documents of the issue in effect on date of use of these test methods form a part of these test methods to the
extent referenced herein:
3
2.2 ASTM Standards:
E4 Practices for Force Verification of Testing Machines
E6 Terminology Relating to Methods of Mechanical Testing
3
E 111 Test Method forYoung’s Modulus, Tangent Modulus, and Chord Modulus Test Method forYoung’s Modulus, Tangent
Modulus, and Chord Modulus
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 In addition to the terms in Terminology E6, the following descriptions of terms apply in connection with these test
methods for determining bend properties:
3.1.2 bendproperties—thosepropertiesofamaterialthatareassociatedwithelasticandinelasticbehaviorwhenabendingforce
is applied, or that involve the relationship between bending stress and strain.
−2
3.1.3 bending stress at outer fiber (FL )—the nominal stress in the outer fibers of a beam resulting from application of a
bending load.
−2
3.1.4 elastic limit in bending (FL )—the greatest bending stress that a material is capable of sustaining without permanent
strain remaining after complete release of the bending moment.
−2
3.1.5 modulus of elasticity in bending (FL )—the ratio of bending stress to corresponding strain below the elastic limit in
bending.
1
These test methods are under the jurisdiction of ASTM Committee E28 on Mechanical Testing and are the direct responsibility of Subcommittee E28.02 on Ductility
and Flexure Testing. Formability.
Current edition approved March 30, 1990.Dec. 1, 2008. Published May 1990.January 2009. Originally published as E855–81.approved in 1981. Last previous edition
E855–84.approved in 2005 as E855–05.
2
Method D, which appeared in the last previous edition, was dropped because of the unavailability of commercial testing equipment.
3
Annual Book of ASTM Standards, Vol 03.01.
3
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,[e-mail] Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
E855–08
3.1.6 span length (L)—the distance between supports.
3.1.7 uniform bending moment (FL)—a bending moment that produces a uniform strain at the outer fibers throughout the gage
length of the specimen.
−2
3.1.8 bending proof strength (FL )—the nominal stress in the outer fibers of a beam that results in a specific permanent strain
in the outer fibers upon unloading.
−2
3.1.9 cyclic bending yield strength (FL )—the maximum nominal s
...

This document is not anASTM standard and is intended only to provide the user of anASTM 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:E855–90(Reapproved 2000) Designation:E855–08
Standard Test Methods for
Bend Testing of Metallic Flat Materials for Spring
1
Applications Involving Static Loading
This standard is issued under the fixed designation E855; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
2
1.1 This standard describes three test methods for determining the modulus of elasticity in bending and the bending strength
of metallic strips or sheets intended for the use in flat springs:
1.1.1 Test Method A—a cantilever beam,
1.1.2 Test Method B—a three-point loaded beam (that is, a beam resting on two supports and centrally loaded), and
1.1.3 Test Method C—afour-pointloadedbeam(thatis,abeamrestingontwosupportsandloadedattwopointsequallyspaced
from each support).
1.2Values stated in inch-pound units are to be regarded as the standard. SI units are provided for information only.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered 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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 The following documents of the issue in effect on date of use of these test methods form a part of these test methods to the
extent referenced herein:
3
2.2 ASTM Standards:
E4 Practices for Force Verification of Testing Machines
E6 Terminology Relating to Methods of Mechanical Testing
3
E 111 Test Method forYoung’s Modulus, Tangent Modulus, and Chord Modulus Test Method forYoung’s Modulus, Tangent
Modulus, and Chord Modulus
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 In addition to the terms in Terminology E6, the following descriptions of terms apply in connection with these test
methods for determining bend properties:
3.1.2 bendproperties—thosepropertiesofamaterialthatareassociatedwithelasticandinelasticbehaviorwhenabendingforce
is applied, or that involve the relationship between bending stress and strain.
−2
3.1.3 bending stress at outer fiber (FL )—the nominal stress in the outer fibers of a beam resulting from application of a
bending load.
−2
3.1.4 elastic limit in bending (FL )—the greatest bending stress that a material is capable of sustaining without permanent
strain remaining after complete release of the bending moment.
−2
3.1.5 modulus of elasticity in bending (FL ) —the ratio of bending stress to corresponding strain below the elastic limit in
bending.
1
These test methods are under the jurisdiction of ASTM Committee E28 on Mechanical Testing and are the direct responsibility of Subcommittee E28.02 on Ductility
and Flexure Testing. Formability.
Current edition approved March 30, 1990.Dec. 1, 2008. Published May 1990.January 2009. Originally published as E855–81.approved in 1981. Last previous edition
E855–84.approved in 2005 as E855–05.
2
Method D, which appeared in the last previous edition, was dropped because of the unavailability of commercial testing equipment.
3
Annual Book of ASTM Standards, Vol 03.01.
3
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,[e-mail] Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
E855–08
3.1.6 span length (L)—the distance between supports.
3.1.7 uniform bending moment (FL)—a bending moment that produces a uniform strain at the outer fibers throughout the gage
length of the specimen.
−2
3.1.8 bending proof strength (FL )—the nominal stress in the outer fibers of a beam that results in a specific permanent strain
in the outer fibers upon unloading.
−2
3.1.9 cyclic bending yield strength (FL )—the maximum nominal
...