ASTM B939-05

Standard Test Method for Radial Crushing Strength, <bdit>K</bdit>, of Powder Metallurgy (P/M) Bearings and Structural Materials

SCOPE
1.1 This test method covers the equipment and laboratory procedure for the determination of the radial crushing strength of materials using either a plain powder metallurgy (P/M) bearing or a hollow cylindrical test specimen. This is a destructive test that produces quantitative results.
1.2 Limitations
1.2.1 The principle of this procedure is based on the material being tested having minimal ductility. The permanent deflection of the cylinder during the test should not exceed 10 % of the outside diameter.
1.2.2 The radial crushing strength test results should be used only as a guide if the test specimen has a wall thickness that is greater than one-third of the outside diameter. These test results should then only be used for comparison with data from the test specimens of like materials and similar dimensions.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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-2005
• ICS: 77.160 - Powder metallurgy
• Technical Committee: B09 - Metal Powders and Metal Powder Products
• Drafting Committee: B09.04 - Bearings

Relations

• Replaced By: ASTM B939-09 - Standard Test Method for Radial Crushing Strength, <bdit>K</bdit>, of Powder Metallurgy (P/M) Bearings and Structural Materials
• Effective Date: 01-Nov-2009
• Referred By: ASTM B438-21 - Standard Specification for Bronze-Base Powder Metallurgy (PM) Bearings (Oil-Impregnated)
• Effective Date: 01-Oct-2005
• Referred By: ASTM B439-21 - Standard Specification for Iron-Base Powder Metallurgy (PM) Bearings (Oil-Impregnated)
• Effective Date: 01-Oct-2005
• Referred By: ASTM B925-15(2022) - Standard Practices for Production and Preparation of Powder Metallurgy (PM) Test Specimens
• Effective Date: 01-Oct-2005

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:B939–05
Standard Test Method for
Radial Crushing Strength,K, of Powder Metallurgy (P/M)
Bearings and Structural Materials
This standard is issued under the fixed designation B939; 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 B438/B438M Specification for Bronze Powder Metallurgy
(P/M) Bearings (Oil-Impregnated)
1.1 This test method covers the equipment and laboratory
B439 Specification for Iron-Base Powder Metallurgy (PM)
procedure for the determination of the radial crushing strength
Bearings (Oil-Impregnated)
of materials using either a plain powder metallurgy (P/M)
B612 Specification for Iron Bronze Sintered Bearings (Oil-
bearing or a hollow cylindrical test specimen. This is a
Impregnated)
destructive test that produces quantitative results.
B782 Specification for Iron Graphite Sintered Bearings
1.2 Limitations:
(Oil-Impregnated)
1.2.1 The principle of this procedure is based on the
B925 Practices for Production and Preparation of Powder
material being tested having minimal ductility. The permanent
Metallurgy (PM) Test Specimens
deflection of the cylinder during the test should not exceed
2.2 MPIF Standard:
10% of the outside diameter.
MPIF Standard 55 Determination of Radial Crush Strength
1.2.2 Theradialcrushingstrengthtestresultsshouldbeused
(K) of Powder Metallurgy Test Specimens
only as a guide if the test specimen has a wall thickness that is
greaterthanone-thirdoftheoutsidediameter.Thesetestresults
3. Terminology
shouldthenonlybeusedforcomparisonwithdatafromthetest
3.1 Definitions—Definitions of powder metallurgy (P/M)
specimens of like materials and similar dimensions.
terms can be found in Terminology B243. Additional descrip-
1.3 The values stated in inch-pound units are to be regarded
tive information is available in the related material section of
as standard. The values given in parentheses are mathematical
Vol 02.05 of the Annual Book of ASTM Standards.
conversions to SI units that are provided for information only
and are not considered standard.
4. Summary of Test Method
1.4 This standard does not purport to address all of the
4.1 Radial crushing strength is determined by subjecting a
safety concerns, if any, associated with its use. It is the
plain sleeve bearing or a thin-walled cylindrical test specimen
responsibility of the user of this standard to establish appro-
to a controlled compressive force applied perpendicular to its
priate safety and health practices and determine the applica-
central axis under uniformly increasing load until fracture
bility of regulatory limitations prior to use.
occurs.
4.2 The term radial crushing strength as used in this test
2. Referenced Documents
2 method is the stress at fracture calculated from the breaking
2.1 ASTM Standards:
load and the dimensions of the test specimen.
B243 Terminology of Powder Metallurgy
5. Significance and Use
This test method is under the jurisdiction of ASTM Committee B09 on Metal
5.1 The radial crushing strength test is a destructive proce-
Powders and Metal Powder Products and is the direct responsibility of Subcom-
dureusedtodetermineamaterialstrengthcharacteristicofP/M
mittee B09.04 on Bearings.
Current edition approved Oct. 1, 2005. Published November 2005. DOI:
10.1520/B0939-05.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Withdrawn. The last approved version of this historical standard is referenced
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM on www.astm.org.
Standards volume information, refer to the standard’s Document Summary page on Available from Metal Powder Industries Federation (MPIF), 105 College Rd.
the ASTM website. East, Princeton, NJ, 08540-6692, USA
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
B939–05
bearings and hollow cylindrical test specimens.These data can 8.2 Wipe the loading plates clean and lay the test specimen
be used to grade, classify, and evaluate the materials. in the central region of the lower plate.
5.2 The P/M bearing Specifications B438/B438M, B439,
8.3 Bringtheupperplateandtestspecimenintocontactand
B612, and B782 require the use of this test method as an
slowlyapplythediametricalloadataratethatdoesnotexceed
acceptance test for the strength of oil-impregnated sintered
0.2 in./min (5 mm/min) (see Fig. 1).
bearings.
8.4 Using a scale on the compression testing machine that
5.3 This test method may be used by powder producers and
has a precision of 1% or better of the crushing load, record to
parts manufacturers as a lot acceptance test for metal powders
the nearest 10 lbf (50 N) the load at which the
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