ASTM C651-15

Standard Test Method for Flexural Strength of Manufactured Carbon and Graphite Articles Using Four-Point Loading at Room Temperature

ABSTRACT
This test method details the standard procedures for determining the flexural strength of manufactured carbon and graphite articles using a simple beam in four-point loading at room temperature. The four-point loading fixture shall consist of spherical bearing blocks of hardened steel or its equivalent to ensure that forces applied to the beam are normal only and without eccentricity, and distortion of the loading member is prevented. Judicious use of linkages, rocker bearings, and flexure plates may maintain the parallel direction of loads and reactions. The test specimens shall be prepared to yield a parallelepiped with cross sections that are rectangular, faces that are parallel and flat, and edges that are free from visible flaws and chips.
SIGNIFICANCE AND USE
4.1 This test method may be used for material development, quality control, characterization, and design data generation purposes.  
4.2 This test method determines the maximum loading on a graphite specimen with simple beam geometry in 4-point bending, and it provides a means for the calculation of flexural strength at ambient temperature and environmental conditions.
SCOPE
1.1 This test method covers determination of the flexural strength of manufactured carbon and graphite articles using a simple beam in four-point loading at room temperature.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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.

General Information

• Status: Historical
• Publication Date: 30-Sep-2015
• ICS: 71.100.99 - Other products of the chemical industry
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.F0 - Manufactured Carbon and Graphite Products

Relations

• Replaces: ASTM C651-13 - Standard Test Method for Flexural Strength of Manufactured Carbon and Graphite Articles Using Four-Point Loading at Room Temperature
• Effective Date: 01-Oct-2015
• Replaced By: ASTM C651-20 - Standard Test Method for Flexural Strength of Manufactured Carbon and Graphite Articles Using Four-Point Loading at Room Temperature
• Effective Date: 01-May-2020
• Referred By: ASTM C198-09(2019) - Standard Test Method for Cold Bonding Strength of Refractory Mortar
• Effective Date: 01-Oct-2015
• Referred By: ASTM C1025-15(2020) - Standard Test Method for Modulus of Rupture in Bending of Electrode Graphite
• Effective Date: 01-Oct-2015
• Referred By: ASTM C781-20 - Standard Practice for Testing Graphite Materials for Gas-Cooled Nuclear Reactor Components
• Effective Date: 01-Oct-2015
• Referred By: ASTM D7846-21 - Standard Practice for Reporting Uniaxial Strength Data and Estimating Weibull Distribution Parameters for Advanced Graphites
• Effective Date: 01-Oct-2015
• Referred By: ASTM D6354-23 - Standard Guide for Sampling Plan and Core Sampling of Carbon Cathode Blocks Used in Aluminum Production
• Effective Date: 01-Oct-2015
• Referred By: ASTM D8255-19 - Standard Guide for Work of Fracture Measurements on Small Nuclear Graphite Specimens
• Effective Date: 01-Oct-2015
• Referred By: ASTM D7775-21 - Standard Guide for Measurements on Small Graphite Specimens
• Effective Date: 01-Oct-2015
• Referred By: ASTM C783-85(2020) - Standard Practice for Core Sampling of Graphite Electrodes
• Effective Date: 01-Oct-2015
• Referred By: ASTM D8377-21a - Standard Guide for High Temperature Strength Measurements of Graphite Impregnated with Molten Salt
• Effective Date: 01-Oct-2015

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: C651 − 15 An American National Standard
Standard Test Method for
Flexural Strength of Manufactured Carbon and Graphite
1
Articles Using Four-Point Loading at Room Temperature
This standard is issued under the fixed designation C651; 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* 4. Significance and Use
1.1 This test method covers determination of the flexural
4.1 This test method may be used for material development,
strength of manufactured carbon and graphite articles using a quality control, characterization, and design data generation
simple beam in four-point loading at room temperature.
purposes.
1.2 The values stated in SI units are to be regarded as 4.2 This test method determines the maximum loading on a
standard. No other units of measurement are included in this
graphite specimen with simple beam geometry in 4-point
standard. bending, and it provides a means for the calculation of flexural
strength at ambient temperature and environmental conditions.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5. Apparatus
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
5.1 The testing machine shall conform to the requirements
bility of regulatory limitations prior to use.
of Practices E4.
5.2 The four-point loading fixture shall consist of bearing
2. Referenced Documents
blocks or cylindrical bearings spaced in a third-point loading
2
2.1 ASTM Standards:
configuration (see Test Method C78).
C78 Test Method for Flexural Strength of Concrete (Using
5.3 The fixture shall ensure that forces applied to the beam
Simple Beam with Third-Point Loading)
are normal only and without eccentricity through the use of
C1161 Test Method for Flexural Strength of Advanced
spherical bearing blocks (see Test Method C78) or articulating
Ceramics at Ambient Temperature
roller bearing assemblies (see Test Method C1161).
E4 Practices for Force Verification of Testing Machines
5.3.1 The bearing block or roller bearing diameter shall be
E177 Practice for Use of the Terms Precision and Bias in
1 1
between ⁄10 and ⁄20 of the specimen support span.Ahardened
ASTM Test Methods
steel bearing block or its equivalent is necessary to prevent
E691 Practice for Conducting an Interlaboratory Study to
distortion of the loading member. Support surfaces must be
Determine the Precision of a Test Method
free to pivot or rotate to relieve frictional constraints.
3. Terminology
5.4 The directions of loads and reactions may be maintained
3.1 Definitions:
parallel by judicious use of linkages, rocker bearings, and
3.1.1 flexural strength, n—property of a solid material that
flexure plates. Eccentricity of loading can be avoided by the
indicates its ability to withstand a flexural or transverse load,
use of spherical bearing blocks or articulating roller bearings.
obtained through a measurement of the ultimate load-carrying
Provision must be made in fixture design for the relief of
capacity of a specified beam in bending.
torsional loading to less than 5 % of the nominal specimen
strength. Refer to the attached figure for a suggested four-point
loading fixture.
1
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.F0 on Manufactured Carbon and Graphite Products.
6. Test Specimen
Current edition approved Oct. 1, 2015. Published November 2015. Originally
6.1 Preparation—The test specimen shall be prepared to
approved in 1970. Last previous edition approved in 2013 as C651 – 13.
DOI:10.1520/C0651-15.
yield a parallelepiped of rectangular cross section. The faces
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
shall be parallel and flat within 0.025 mm⁄mm of length. In
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
addition, the samples having a maximum particle size less than
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 0.150 mm in diameter must be finished so that the surface
*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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C651 − 15
roughness is less than 3 µm Ra. Sample edges should be free
S = flexural
...

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: C651 − 13 C651 − 15 An American National Standard
Standard Test Method for
Flexural Strength of Manufactured Carbon and Graphite
1
Articles Using Four-Point Loading at Room Temperature
This standard is issued under the fixed designation C651; 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 This test method covers determination of the flexural strength of manufactured carbon and graphite articles using a simple
beam in four-point loading at room temperature.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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
2.1 ASTM Standards:
C78 Test Method for Flexural Strength of Concrete (Using Simple Beam with Third-Point Loading)
C709 Terminology Relating to Manufactured Carbon and Graphite
C1161 Test Method for Flexural Strength of Advanced Ceramics at Ambient Temperature
E4 Practices for Force Verification of Testing Machines
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—For definitions of terms relating to manufactured carbon and graphite, see Terminology C709.
3.1 Definitions of Terms Specific to This Standard:Definitions:
3.1.1 flexural strength—strength, n—a measure property of a solid material that indicates its ability to withstand a flexural or
transverse load, obtained through a measurement of the ultimate load-carrying capacity of a specified beam in bending.
4. Significance and Use
4.1 This test method may be used for material development, quality control, characterization, and design data generation
purposes.
4.2 This test method determines the maximum loading on a graphite specimen with simple beam geometry in 4–point4-point
bending, and it provides a means for the calculation of flexural strength at ambient temperature and environmental conditions.
5. Apparatus
5.1 The testing machine shall conform to the requirements of Practices E4.
5.2 The four-point loading fixture shall consist of bearing blocks or cylindrical bearings spaced in a third-point loading
configuration (see Test Method C78).
1
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.F0 on Manufactured Carbon and Graphite Products.
Current edition approved Oct. 1, 2013Oct. 1, 2015. Published November 2013November 2015. Originally approved in 1970. Last previous edition approved in 20112013
as C651 – 11.C651 – 13. DOI:10.1520/C0651–13.DOI:10.1520/C0651-15.
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

---------------------- Page: 1 ----------------------
C651 − 15
5.3 The fixture shall ensure that forces applied to the beam are normal only and without eccentricity through the use of spherical
bearing blocks (see Test Method C78) or articulating roller bearing assemblies (see Test Method C1161).
1 1
5.3.1 The bearing block or roller bearing diameter shall be between 1/10 ⁄10 and 1/20 ⁄20 of the specimen support span. A
hardened steel bearing block or its equivalent is necessary to prevent distortion of the loading member. Support surfaces must be
free to pivot or rotate to relieve frictional constraints.
5.4 The directions of loads and reactions may be maintained parallel by judicious use of linkages, rocker bearings, and flexure
plates. Eccentricity of loading can be avoided by the use of spherical bearing blocks or articulating rol
...