ASTM D6272-17e1
(Test Method)Standard Test Method for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials by Four-Point Bending
Standard Test Method for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials by Four-Point Bending
SIGNIFICANCE AND USE
5.1 Flexural properties determined by this test method are especially useful for quality control and specification purposes.
5.2 This test method is recommended for those materials that do not fail within the strain limits imposed by Test Method D790. The major difference between four point and three point bending modes is the location of the maximum bending moment and maximum axial fiber stress. In four point bending the maximum axial fiber stress is uniformly distributed between the loading noses. In three point bending the maximum axial fiber stress is located immediately under the loading nose.
5.3 Flexural properties vary with specimen depth, temperature, atmospheric conditions, and the difference in rate of straining specified in Procedures A and B.
5.4 Before proceeding with this test method, reference the specification of the material being tested. Any test specimen preparation, conditioning, dimensions, or testing parameters covered in the material specification, or both, shall take precedence over those mentioned in this test method. If there are no material specifications, then these default conditions apply. Table 1 in Classification D4000 lists the ASTM materials standards that currently exist.
SCOPE
1.1 This test method covers the determination of flexural properties of unreinforced and reinforced plastics, including high-modulus composites and electrical insulating materials in the form of rectangular bars molded directly or cut from sheets, plates, or molded shapes. These test methods are generally applicable to rigid and semirigid materials. However, flexural strength cannot be determined for those materials that do not break or that do not fail in the outer fibers. This test method utilizes a four point loading system applied to a simply supported beam.
1.2 This test method describes two procedures (Procedure A and Procedure B), the selection of which depends on the behavior of the sample to be tested as explained below:
1.2.1 Procedure A, designed principally for materials that break at comparatively small deflections. It shall be used for measurement of flexural properties, particularly flexural modulus, unless the material specification states otherwise.
1.2.2 Procedure B, designed particularly for those materials that undergo large deflections during testing. It is suitable for measurement of flexural strength.
1.3 Comparative tests are permitted to be run according to either procedure, provided that the procedure is found satisfactory for the material being tested.
1.4 The values stated in SI units are to be regarded as the standard. The values provided in parentheses are for information only.
1.5 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.
Note 1: This test method is similar to ISO 14125, Method B. However, ISO 14125, Method B specifies only a load span of 1/3 the support span whereas D6272 also permits a load span of 1/2 the support span. For this reason and other differences in technical content, exercise extreme care if attempting to compare results between the two test methods.
1.6 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
Relations
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.
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Designation: D6272 − 17
Standard Test Method for
Flexural Properties of Unreinforced and Reinforced Plastics
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and Electrical Insulating Materials by Four-Point Bending
This standard is issued under the fixed designation D6272; 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.
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ε NOTE—Editorially corrected 7.2.2 in July 2020.
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However, ISO 14125, Method B specifies only a load span of ⁄3 the
1. Scope*
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support span whereas D6272 also permits a load span of ⁄2 the support
1.1 This test method covers the determination of flexural
span. For this reason and other differences in technical content, exercise
properties of unreinforced and reinforced plastics, including extreme care if attempting to compare results between the two test
methods.
high-modulus composites and electrical insulating materials in
theformofrectangularbarsmoldeddirectlyorcutfromsheets, 1.6 This international standard was developed in accor-
plates, or molded shapes. These test methods are generally
dance with internationally recognized principles on standard-
applicable to rigid and semirigid materials. However, flexural ization established in the Decision on Principles for the
strength cannot be determined for those materials that do not
Development of International Standards, Guides and Recom-
break or that do not fail in the outer fibers. This test method mendations issued by the World Trade Organization Technical
utilizes a four point loading system applied to a simply
Barriers to Trade (TBT) Committee.
supported beam.
2. Referenced Documents
1.2 This test method describes two procedures (ProcedureA
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2.1 ASTM Standards:
and Procedure B), the selection of which depends on the
D618 Practice for Conditioning Plastics for Testing
behavior of the sample to be tested as explained below:
D638 Test Method for Tensile Properties of Plastics
1.2.1 Procedure A, designed principally for materials that
D790 Test Methods for Flexural Properties of Unreinforced
break at comparatively small deflections. It shall be used for
and Reinforced Plastics and Electrical Insulating Materi-
measurement of flexural properties, particularly flexural
als
modulus, unless the material specification states otherwise.
D883 Terminology Relating to Plastics
1.2.2 Procedure B, designed particularly for those materials
D4000 Classification System for Specifying Plastic Materi-
that undergo large deflections during testing. It is suitable for
als
measurement of flexural strength.
D5947 Test Methods for Physical Dimensions of Solid
1.3 Comparative tests are permitted to be run according to
Plastics Specimens
either procedure, provided that the procedure is found satisfac-
E4 Practices for Force Verification of Testing Machines
tory for the material being tested.
E83 Practice for Verification and Classification of Exten-
1.4 The values stated in SI units are to be regarded as the
someter Systems
standard. The values provided in parentheses are for informa-
E691 Practice for Conducting an Interlaboratory Study to
tion only.
Determine the Precision of a Test Method
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2.2 ISO Standard:
1.5 This standard does not purport to address all of the
ISO 14125 (Method B) Fibre-Reinforced Plastic
safety concerns, if any, associated with its use. It is the
Composites—Determination of Flexural Properties
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
3. Terminology
mine the applicability of regulatory limitations prior to use.
3.1 Definitions:
NOTE 1—This test method is similar to ISO 14125, Method B.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
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This test method is under the jurisdiction ofASTM Committee D20 on Plastics contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved March 1, 2017. Published March 2017. Originally the ASTM website.
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approved in 1998. Last previous edition approved in 2010 as D6272 - 10. DOI: Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
10.1520/D6272-17E01. 4th Floor, New York, NY 10036, http://www.ansi.org.
*A Summary of Changes section appears at the end of this standard
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