ASTM E238-84(2008)
(Test Method)Standard Test Method for Pin-Type Bearing Test of Metallic Materials
Standard Test Method for Pin-Type Bearing Test of Metallic Materials
SIGNIFICANCE AND USE
The data obtained from the bearing test are the bearing ultimate and yield strength. The data provide a measure of the load-carrying capacity of a material edge loaded with a close-fitting cylindrical pin through a hole located a specific distance from the specimen edge.
Bearing properties are useful in the comparison of materials and design of structures under conditions where the pin is not restricted.
SCOPE
1.1 This test method covers a pin-type bearing test of metallic materials to determine bearing yield strength and bearing strength.
Note 1—The presence of incidental lubricants on the bearing surfaces may significantly lower the value of bearing yield strength obtained by this method.
1.2 Units—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.
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Designation:E238–84 (Reapproved 2008)
Standard Test Method for
Pin-Type Bearing Test of Metallic Materials
This standard is issued under the fixed designation E238; 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
1.1 This test method covers a pin-type bearing test of
metallic materials to determine bearing yield strength and
bearing strength.
NOTE 1—The presence of incidental lubricants on the bearing surfaces
may significantly lower the value of bearing yield strength obtained by
this method.
1.2 Units—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 appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
E4 Practices for Force Verification of Testing Machines
E6 TerminologyRelatingtoMethodsofMechanicalTesting
E83 Practice for Verification and Classification of Exten-
FIG. 1 Bearing Test Specimen
someter Systems
3. Terminology 3.1.4 bearing yield strength—the bearing stress at which a
material exhibits a specified limiting deviation from the pro-
3.1 Definitions:
portionality of bearing stress to bearing strain.
3.1.1 bearing area—the product of the pin diameter and
3.1.5 bearing strength—the maximum bearing stress which
specimen thickness.
a material is capable of sustaining.
3.1.2 bearing stress—the force per unit of bearing area.
3.1.6 edge distance—the distance from the edge of a bear-
3.1.3 bearing strain—the ratio of the bearing deformation
ing specimen to the center of the hole in the direction of
of the bearing hole, in the direction of the applied force, to the
applied force (Fig. 1).
pin diameter.
3.1.7 edge distance ratio—the ratio of the edge distance to
the pin diameter.
This test method is under the jurisdiction of ASTM Committee E28 on
3.1.8 For definitions of other terms see Terminology E6.
Mechanical Testing and is the direct responsibility of Subcommittee E28.04 on
Uniaxial Testing.
4. Significance and Use
Current edition approved May 1, 2008. Published December 2008. Originally
4.1 The data obtained from the bearing test are the bearing
approved in 1964. Last previous edition approved in 2002 as E238 – 84 (2002).
DOI: 10.1520/E0238-84R08.
ultimate and yield strength. The data provide a measure of the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
load-carrying capacity of a material edge loaded with a
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
close-fitting cylindrical pin through a hole located a specific
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. distance from the specimen edge.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E238–84 (2008)
TABLE 1 Characteristics of Pin for Various Materials Tested
possible. If the specimen is too thick in relation to the pin
Rockwell Surface Roughness, diameter, the pin is liable to bend considerably or break before
Material Tested Material
Hardness µ in. (µm) (avg)
the bearing strength is obtained. If a specimen is too thin,
Aluminum alloys hardened steel C60 to 64 4 to 8 (0.1 to 0.2 µm)
buckling may occur. A ratio of pin diameter to specimen
Beryllium alloys hardened steel C60 to 64 4 to 8 (0.1 to 0.2 µm)
thicknessoffrom2to4hasbeenusedtoavoidbothconditions.
Copper alloys hardened steel C60 to 64 4 to 8 (0.1 to 0.2µ m)
Magnesium alloys hardened steel C60 to 64 4 to 8 (0.1 to 0.2 µm) The hole should have approximately the same diameter as for
Zinc alloys hardened steel C60 to 64 4 to 8 (0.1 to 0.2µ m)
the intended use. For example, if the bearing test results are
3 1
being used to obtain data for a riveted part, a hole ⁄16 in. or ⁄4
in. (5 or 6 mm) in diameter would be suitable, while for a
4.2 Bearing properties are useful in the comparison of
bolted assembly, a larger hole might be desirable.Adifference
materials and design of structures under conditions where the
in test results may be obtained with holes of different diam-
pin is not restricted.
eters. The width of the specimen should be about 4 to 8 times
5. Apparatus
theholediameter.Theedgedistanceratioshallbespecifiedand
5.1 Testing Machines—Machines used for bearing testing
the edge distance held within a tolerance of 62 %. Edge
shall conform to the requirements of Practices E4.
distance ratios of 1 ⁄2 and 2 are commonly used (see Fig. 1).A
5.2 Gripping Devices—Various types of gripping devices
close fit between the specimen and pin is required since a loose
may be used to transmit the measured load applied by the
fit will tend to give lower results. The diameter of the hole
testing machine to the test specimens.Any grips considered to
should not exceed the pin diameter by more than 0.001 in.
apply the load axially for tension testing, such as pin connec-
(0.02 mm). The total length of the test specimen is not critical
tions or wedge grips, are satisfactory for use in bearing testing.
and may depend on the method used to grip the specimen. Fig.
5.3 Pin—The bearing load is generally applied to the
1 shows a bearing test specimen commonly used.
specimen through a close-fitting cylindrical pin. The pin shall
6.2 Specimen Preparation—A flat specimen with a hole
be harder and stronger than the material being tested. Restraint
normal to the face shall be used. A smooth, round hole with a
ofmovementofthespecimenwhereitisincontactwiththepin
minimum of cold work on the surface must be obtained. The
hasaconsiderableeffectupontheholedeformationobtainedas
finished hole is generally bored, reamed, or ground as a final
a function of the load applied. Close control of surface
operation to obtain the desired degree of roundness. Any burr
conditions on both the specimen and pin is needed to assure
on the periphery of the hole is indicative of a cold-worked
reproducible results. The pins used should be uniform in
surfaceontheholeandshouldbeavoided.Removaloftheburr
diameter, hardness, and surface roughness. Pin materials,
will not eliminate the cold work.
hardness, and surface roughness as shown in Table 1 are
reco
...
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:E238–84 (Reapproved 2002) Designation:E238–84 (Reapproved 2008)
Standard Test Method for
Pin-Type Bearing Test of Metallic Materials
This standard is issued under the fixed designation E 238; 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
1.1 This test method covers a pin-type bearing test of metallic materials to determine bearing yield strength and bearing
strength.
NOTE 1—The presence of incidental lubricants on the bearing surfaces may significantly lower the value of bearing yield strength obtained by this
method.
1.2The values stated in inch-pound units are to be regarded as the standard.
1.2 Units—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 ASTM Standards:
E4 Practices for Force Verification of Testing Machines
E6 Terminology Relating to Methods of Mechanical Testing
E83 Practice for Verification and Classification of Extensometer Systems
3. Terminology
3.1 Definitions:
3.1.1 bearing area—the product of the pin diameter and specimen thickness.
3.1.2 bearing stress—the force per unit of bearing area.
3.1.3 bearing strain—the ratio of the bearing deformation of the bearing hole, in the direction of the applied force, to the pin
diameter.
3.1.4 bearing yield strength—the bearing stress at which a material exhibits a specified limiting deviation from the
proportionality of bearing stress to bearing strain.
3.1.5 bearing strength—the maximum bearing stress which a material is capable of sustaining.
3.1.6 edge distance—the distance from the edge of a bearing specimen to the center of the hole in the direction of applied force
(Fig. 1).
3.1.7 edge distance ratio—the ratio of the edge distance to the pin diameter.
3.1.8 For definitions of other terms see Terminology E 6.
4. Significance and Use
4.1 The data obtained from the bearing test are the bearing ultimate and yield strength. The data provide a measure of the
load-carrying capacity of a material edge loaded with a close-fitting cylindrical pin through a hole located a specific distance from
the specimen edge.
4.2 Bearing properties are useful in the comparison of materials and design of structures under conditions where the pin is not
restricted.
This test method is under the jurisdiction of ASTM Committee E28 on Mechanical Testing and is the direct responsibility of Subcommittee E28.05 on Compression
Testing.
Current edition approved July 27, 1984. Published November 1984. Originally published as E238–64. Last previous edition E238–68 (1978).
This test method is under the jurisdiction ofASTM Committee E28 on Mechanical Testing and is the direct responsibility of Subcommittee E28.04 on Uniaxial Testing.
Current edition approved May 1, 2008. Published December 2008. Originally approved in 1964. Last previous edition approved in 2002 as E 238 – 84 (2002).
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
, Vol 03.01.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.
E238–84 (2008)
FIG. 1 Bearing Test Specimen
5. Apparatus
5.1 Testing Machines—Machines used for bearing testing shall conform to the requirements of Practices E 4.
5.2 Gripping Devices—Various types of gripping devices may be used to transmit the measured load applied by the testing
machine to the test specimens.Any grips considered to apply the load axially for tension testing, such as pin connections or wedge
grips, are satisfactory for use in bearing testing.
5.3 Pin—The bearing load is generally applied to the specimen through a close-fitting cylindrical pin. The pin shall be harder
and stronger than the material being tested. Restraint of movement of the specimen where it is in contact with the pin has a
considerable effect upon the hole deformation obtained as a function of the load applied. Close control of surface conditions on
both the specimen and pin is needed to assure reproducible results. The pins used should be uniform in diameter, hardness, and
surface roughness. Pin materials, hardness, and surface roughness as shown in Table 1 are recommended for testing the materials
listed. The pin should be checked carefully after each test to ensure that no metallic residue adheres to it and that it is both straight
and undeformed. If there is any question regarding its quality it should be replaced.
5.4 Pin Support—The jig supporting the pin should position the pin concentric with the hole in the specimen. It should not
restrain the thickening of the specimen as the load from the pin deforms the hole. Bending of the pin should be kept to a minimum
by having the jig support the pin close to the specimen. Fig. 2 and Fig. 3 show examples of the types of jig that have been used
and are considered satisfactory.
5.5 Extensometers—Extensometers used for measuring the bearing deformation shall comply with the requirements for Class
B-2 or better as described in Practice E 83. The bearing deformation measurement shall be made in a manner to obtain the axial
bearing deformation with a minimum of other deformations being included such as the bending of the pin and tensile strain in the
specimen. Fig. 2 shows an adaptation of a Templin extensometer system to record bearing deformation. Fig. 3 illustrates a
mechanismthatcanbeusedtotransferthebearingdeformationsoitcanbemeasuredwiththesameextensometersusedfortension
testing. A method of measuring bearing deformation featuring two linear differential transformers is shown in Fig. 4.
6. Test Specimens
6.1 Specimen Dimensions—The specimen shall be a flat sheet type, with the full thickness of the product being used if possible.
Ifthespecimenistoothickinrelationtothepindiameter,thepinisliabletobendconsiderablyorbreakbeforethebearingstrength
TABLE 1 Characteristics of Pin for Various Materials Tested
Rockwell Surface Roughness,
Material Tested Material
Hardness µ in. (µm) (avg)
Aluminum alloys hardened steel C60 to 64 4 to 8 (0.1 to 0.2
...
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