ASTM B438/B438M-05

Specification for Bronze Powder Metallurgy (P/M) Bearing (Oil-Impregnated)

SCOPE
1.1 This specification covers sintered bronze, oil-impregnated bearings made primarily from elemental copper, tin, lead, and graphite powders. The manufacturer may, at his discretion, use prealloyed bronze powder in the mixed powder.
1.2 This specification covers the following variables:
1.2.1 GradesAvailable in three bronze base compositions identifiable by different graphite contents and one leaded bronze grade.
1.2.2 TypeGrades 1 and 2 are available in four types described by specific density ranges. Grade 3 is available in two types and Grade 4 is available in one type.
1.3 Bearings ordered to this specification will normally be sized after sintering and will be impregnated with a lubricating oil unless otherwise specified by the print.
1.4 The values stated in either inch-pound or SI units are to be regarded separately as standard. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with this specification.
1.5 The following safety hazards caveat pertains only to the test methods described in this specification. 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: 31-Oct-2005
• ICS: 21.100.01 - Bearings in general
• Technical Committee: B09 - Metal Powders and Metal Powder Products
• Drafting Committee: B09.04 - Bearings

Relations

• Replaces: ASTM B438/B438M-04 - Standard Specification for Sintered Bronze Bearings (Oil-Impregnated)
• Effective Date: 01-Nov-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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: B 438/B 438M – 05
Standard Specification for
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Bronze Powder Metallurgy (P/M) Bearings (Oil-Impregnated)
This standard is issued under the fixed designation B 438/B 438M; 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 (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope B 328 Test Method for Density, Oil Content, and Intercon-
nected Porosity of Sintered Metal Structural Parts and
1.1 This specification covers sintered bronze, oil-
Oil-Impregnated Bearings
impregnated bearings made primarily from elemental copper,
B 939 Test Method for Radial Crushing Strength, K, of
tin, lead, and graphite powders. The manufacturer may, at his
Powder Metallurgy (P/M), Bearings and Structural Mate-
discretion, use prealloyed bronze powder in the mixed powder.
rials
1.2 This specification covers the following variables:
E9 Test Methods of Compression Testing of Metallic Ma-
1.2.1 Grades—Available in three bronze base compositions
terials at Room Temperature
identifiable by different graphite contents and one leaded
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2.2 Government Standards:
bronze grade.
MIL-PRF-6085 Lubricating Oil: Instrument, Aircraft, Low
1.2.2 Type—Grades 1 and 2 are available in four types
Volatility
described by specific density ranges. Grade 3 is available in
MIL-PRF-17331 Lubrication Oil: Steam Turbine and Gear,
two types and Grade 4 is available in one type.
Moderate Service
1.3 Bearings ordered to this specification will normally be
FED-STD-151 Metals Test Method
sized after sintering and will be impregnated with a lubricating
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2.3 MPIF Standard:
oil unless otherwise specified by the print.
MPIF Standard 35 Materials Standards for P/M Self-
1.4 The values stated in either inch-pound or SI units are to
Lubricating Bearings
be regarded separately as standard. The values stated in each
system are not exact equivalents; therefore, each system shall
3. Ordering Information
be used independently of the other. Combining values from the
3.1 Ordersforbearingsunderthisspecificationshallinclude
two systems may result in nonconformance with this specifi-
the following information:
cation.
3.1.1 Dimensions and tolerances (Section 9),
1.5 The following safety hazards caveat pertains only to the
3.1.2 Grade and type (see Tables 1-5),
test methods described in this specification.Thisstandarddoes
3.1.3 Wet density specification (Table 2 and Table 3), and
not purport to address all of the safety concerns, if any,
3.1.4 Oil type.
associatedwithitsuse.Itistheresponsibilityoftheuserofthis
standard to establish appropriate safety and health practices
4. Materials and Manufacture
and determine the applicability of regulatory limitations prior
4.1 Sintered bronze bearings shall be made by molding or
to use.
briquetting metal powder mixtures to the proper density. The
2. Referenced Documents green bearing shall be sintered at a time–temperature relation-
2 shiptoproduceamicrostructurethatisessentiallyalphabronze
2.1 ASTM Standards:
and contains no tin-rich phases visible at 3003. Sintered
bronze bearings are normally sized after sintering to maintain
the dimensional characteristics required of the bearing. After
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This specification is under the jurisdiction ofASTM Committee B09 on Metal
sizing and inspection, they are impregnated with a lubricating
Powders and Metal Powder Products and is the direct responsibility of Subcom-
oil unless otherwise specified.
mittee B09.04 on Bearings.
Current edition approved Nov. 1, 2005. Published November 2005. Originally
approved in 1966. Last previous edition approved in 2004 as B 438/B 438M – 04.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Robbins Ave., Philadelphia, PA 19111–5094, Attn: NPODS.
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Standards volume information, refer to the standard’s Document Summary page on AvailablefromMetalPowdersIndustriesFederation(MPIF),105CollegeRoad
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.
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B 438/B 438M – 05
TABLE 1 Chemical Requirements (Composition, %) TABLE 5 Minimum Radial Crushing Strength for Bronze
Bearings (Oil-Impregnated)
Element Grade 1 Grade 2 Grade 3 Grade 4
Grade Type Minimum Strength
Copper 87.2–90.5 85.7–90.0 82.8–88.3 80.9–88.0
Tin 9.5–10.5 9.5–10.5 9.2–10.2 9.5–10.5
Bronze Wet K
Graphite 0–0.3 0.5–1.8 2.5–5.0 0.50–1.75
...