ASTM B438-21

Standard Specification for Bronze-Base Powder Metallurgy (PM) Bearings (Oil-Impregnated)

ABSTRACT
This specification covers sintered bronze, oil-impregnated bearings made primarily from elemental copper, tin, lead, and graphite powders. This specification covers the following variables: Grades (available in three bronze base compositions identifiable by different graphite contents and one leaded bronze grade) and Type (Grades 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). Sintered bronze bearings shall be made by molding or briquetting metal powder mixtures to the proper density. The material shall conform to the required chemical composition for copper, tin, graphite, iron, lead, zinc, nickel, and antimony. The density of bearings supplied impregnated with lubricant shall be within the prescribed limits. Oil content of bearings shall not be less than the prescribed value for each grade and type of material. The material of different grades and types shall conform to the prescribed radial crushing strength requirements. An acceptance specification for the minimum bearing breaking load may be established for any specific standard oil-impregnated bearing. Chemical analysis shall be made for each representative sample of chips, which may be obtained by milling, drilling, filing, or crushing a bearing with clean dry tools without lubrication.
SCOPE
1.1 This specification covers porous metallic sleeve, flange, thrust, and spherical bronze-base bearings that are produced from mixed metal powders utilizing powder metallurgy (PM) technology and then impregnated with oil to supply operating lubrication.  
1.2 Included are the specifications for the chemical, physical, and mechanical requirements of those bronze-base PM materials that have been developed and standardized specifically for use in the manufacture of these self-lubricating bearings.  
1.3 This specification is applicable to the purchase of bronze-base bearings (oil-impregnated) that were formerly covered by military specifications and are intended for government or military applications. Those additional government requirements that only apply to military bearings are listed in the Supplementary Requirements section of this specification.  
1.4 This specification accompanies Specification B439 that covers the requirements for Iron-Base Powder Metallurgy (PM) Bearings, (Oil-Impregnated).  
1.5 Typical applications for bronze-base bearings are listed in Appendix X1.  
1.6 Bearing dimensional tolerance data are shown in Appendix X2, while engineering information regarding installation and operating parameters of PM bearings is included in Appendix X3. Additional useful information on self-lubricating bearings can be found in MPIF Standard 35, ISO 5755 and the technical literature.2  
1.7 With the exception of the values for density and the mass used to determine density, for which the use of the gram per cubic centimetre (g/cm3) and gram (g) units is the industry standard, 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.  
1.8 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.9 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

• Status: Published
• Publication Date: 31-Mar-2021
• ICS: 21.100.01 - Bearings in general
• Technical Committee: B09 - Metal Powders and Metal Powder Products
• Drafting Committee: B09.04 - Bearings

Relations

• Refers: ASTM B963-24 - Standard Test Methods for Oil Content, Oil-Impregnation Efficiency, and Surface-Connected Porosity of Sintered Powder Metallurgy (PM) Products Using Archimedes’ Principle
• Effective Date: 01-Feb-2024
• Refers: ASTM B243-18 - Standard Terminology of Powder Metallurgy
• Effective Date: 01-Oct-2018
• Refers: ASTM B243-16 - Standard Terminology of Powder Metallurgy
• Effective Date: 01-Jul-2016
• Refers: ASTM B962-15 - Standard Test Methods for Density of Compacted or Sintered Powder Metallurgy (PM) Products Using Archimedes’ Principle
• Effective Date: 01-Apr-2015
• Refers: ASTM B963-14 - Standard Test Methods for Oil Content, Oil-Impregnation Efficiency, and Surface-Connected Porosity of Sintered Powder Metallurgy (PM) Products Using Archimedes’ Principle
• Effective Date: 01-Sep-2014
• Refers: ASTM B962-14 - Standard Test Methods for Density of Compacted or Sintered Powder Metallurgy (PM) Products Using Archimedes’ Principle
• Effective Date: 01-Sep-2014
• Refers: ASTM B243-13 - Standard Terminology of Powder Metallurgy
• Effective Date: 01-Nov-2013
• Refers: ASTM B963-13 - Standard Test Methods for Oil Content, Oil-Impregnation Efficiency, and Interconnected Porosity of Sintered Powder Metallurgy (PM) Products Using Archimedes’ Principle
• Effective Date: 01-Apr-2013
• Refers: ASTM B962-13 - Standard Test Methods for Density of Compacted or Sintered Powder Metallurgy (PM) Products Using Archimedes’ Principle
• Effective Date: 01-Apr-2013
• Refers: ASTM B243-12 - Standard Terminology of Powder Metallurgy
• Effective Date: 15-Jul-2012
• Refers: ASTM B439-12 - Standard Specification for Iron-Base Powder Metallurgy (PM) Bearings (Oil-Impregnated)
• Effective Date: 01-Apr-2012
• Refers: ASTM B243-11 - Standard Terminology of Powder Metallurgy
• Effective Date: 15-Nov-2011
• Refers: ASTM B963-11 - Standard Test Methods for Oil Content, Oil-Impregnation Efficiency, and Interconnected Porosity of Sintered Powder Metallurgy (PM) Products Using Archimedes<span class='unicode'>&#x2019;</span> Principle
• Effective Date: 01-May-2011
• Refers: ASTM B946-11 - Standard Test Method for Surface Finish of Powder Metallurgy (P/M) Products
• Effective Date: 01-May-2011
• Refers: ASTM E1019-11 - Standard Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys by Various Combustion and Fusion Techniques
• Effective Date: 15-Mar-2011

Overview

ASTM B438-21: Standard Specification for Bronze-Base Powder Metallurgy (PM) Bearings (Oil-Impregnated) defines the requirements for porous metallic bearings produced using powder metallurgy and subsequently oil-impregnated to deliver self-lubricating performance. This international standard covers bronze-base bearings including sleeve, flange, thrust, and spherical designs manufactured primarily from copper, tin, lead, and graphite powders. ASTM B438-21 is widely used in industries that require reliable self-lubricating bushings and bearings for machinery, automotive, aerospace, and defense applications. The specification ensures consistency in chemical, physical, and mechanical properties for high performance in demanding environments.

Key Topics

• Types and Grades:
  The standard classifies bronze-base PM bearings into several grades and types, distinguished by composition (copper, tin, graphite, and optional lead) and density range. Common grades include low, medium, and high graphite, as well as military-specific leaded bronze.

• Material and Manufacturing Requirements:
  Bearings are produced by compacting and sintering metal powders to achieve the desired porosity and mechanical strength. After sintering, parts are impregnated with lubricating oil, either by soaking or vacuum impregnation, to fill interconnected porosity and achieve efficient self-lubrication.

• Chemical and Mechanical Properties:
  The specification provides detailed guidelines for permissible chemical composition (copper, tin, lead, iron, graphite, plus limits on zinc, nickel, and antimony), oil content, impregnated density, and radial crushing strength of the bearing materials.

• Oil Impregnation and Lubrication:
  Bearings must be filled with oil to specific minimum levels to ensure continuous lubrication during service. The oil used is typically a medium viscosity petroleum lubricant, with options to specify other grades for special requirements or military applications.

• Dimensional and Tolerance Requirements:
  ASTM B438-21 includes recommendations for bearing dimensions and tolerances, referencing both commercial and military procurement needs. Detailed drawings and appendices provide guidance for installation and optimal performance.

Applications

Bronze-base powder metallurgy (PM) bearings specified by ASTM B438-21 are widely applied in:

• General industrial machinery (motors, conveyors, fans)
• Automotive applications (transmissions, steering columns, electric motors)
• Small appliances (home electronics, tools, office equipment)
• Aerospace and defense systems requiring oil-impregnated, maintenance-free bearings
• Government and military equipment, replacing previously military-only standards

Self-lubricating bronze PM bearings are especially advantageous where periodic maintenance is limited, where lubrication access is restricted, or in environments requiring low friction and long service life.

Related Standards

ASTM B438-21 cross-references several important standards and resources for producers, designers, and purchasers:

• ASTM B243: Terminology of Powder Metallurgy
• ASTM B439: Iron-Base Powder Metallurgy (PM) Bearings (Oil-Impregnated)
• ASTM B939, B946, B962, B963: Test methods for radial strength, surface finish, density, oil content, and porosity by Archimedes’ Principle
• MPIF Standard 35: Materials Standards for PM Self-Lubricating Bearings
• ISO 5755: Sintered Metal Materials - Specifications
• ISO 2795: Plain Bearings Made from Sintered Material-Dimensions and Tolerances
• Relevant military oil and lubrication standards (e.g., MIL-PRF-6085, MIL-PRF-17331)

Practical Value

By specifying material grades, manufacturing methods, and quality assurance approaches, ASTM B438-21 ensures the consistent performance of PM bronze bearings in self-lubricated applications. Adoption of this standard allows manufacturers and end-users to:

• Achieve predictable service lifespans for critical machinery
• Ensure interchangeability and compatibility of parts
• Meet procurement requirements for government and military use
• Streamline quality control through referenced test methods and certifications

Implementing ASTM B438-21 helps industries reduce downtime, improve reliability, and minimize the need for maintenance in bearing applications.

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.
Designation:B438 −21
Standard Specification for
Bronze-Base Powder Metallurgy (PM) Bearings (Oil-
Impregnated)
This standard is issued under the fixed designation B438; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* regarded as standard. The values given in parentheses are
mathematical conversions to SI units that are provided for
1.1 This specification covers porous metallic sleeve, flange,
information only and are not considered standard.
thrust, and spherical bronze-base bearings that are produced
1.8 The following safety hazards caveat pertains only to the
from mixed metal powders utilizing powder metallurgy (PM)
test methods described in this specification. This standard does
technology and then impregnated with oil to supply operating
not purport to address all of the safety concerns, if any,
lubrication.
associated with its use. It is the responsibility of the user of this
1.2 Included are the specifications for the chemical,
standard to establish appropriate safety, health, and environ-
physical, and mechanical requirements of those bronze-base
mental practices and determine the applicability of regulatory
PM materials that have been developed and standardized
limitations prior to use.
specifically for use in the manufacture of these self-lubricating
1.9 This international standard was developed in accor-
bearings.
dance with internationally recognized principles on standard-
1.3 This specification is applicable to the purchase of
ization established in the Decision on Principles for the
bronze-base bearings (oil-impregnated) that were formerly
Development of International Standards, Guides and Recom-
coveredbymilitaryspecificationsandareintendedforgovern-
mendations issued by the World Trade Organization Technical
ment or military applications. Those additional government
Barriers to Trade (TBT) Committee.
requirements that only apply to military bearings are listed in
the Supplementary Requirements section of this specification. 2. Referenced Documents
1.4 This specification accompanies Specification B439 that
2.1 ASTM Standards:
covers the requirements for Iron-Base Powder Metallurgy
B243Terminology of Powder Metallurgy
(PM) Bearings, (Oil-Impregnated).
B439Specification for Iron-Base Powder Metallurgy (PM)
Bearings (Oil-Impregnated)
1.5 Typical applications for bronze-base bearings are listed
B939Test Method for Radial Crushing Strength, K,of
in Appendix X1.
Powder Metallurgy (PM) Bearings and Structural Materi-
1.6 Bearing dimensional tolerance data are shown in Ap-
als
pendix X2, while engineering information regarding installa-
B946Test Method for Surface Finish of Powder Metallurgy
tion and operating parameters of PM bearings is included in
(PM) Products
Appendix X3. Additional useful information on self-
B962Test Methods for Density of Compacted or Sintered
lubricating bearings can be found in MPIF Standard 35, ISO
Powder Metallurgy (PM) Products Using Archimedes’
5755 and the technical literature.
Principle
1.7 With the exception of the values for density and the B963 Test Methods for Oil Content, Oil-Impregnation
mass used to determine density, for which the use of the gram Efficiency, and Surface-Connected Porosity of Sintered
per cubic centimetre (g/cm ) and gram (g) units is the industry Powder Metallurgy (PM) Products Using Archimedes’
standard, the values stated in inch-pound units are to be Principle
E9Test Methods of Compression Testing of Metallic Mate-
rials at Room Temperature
This specification is under the jurisdiction ofASTM Committee B09 on Metal
Powders and Metal Powder Products and is the direct responsibility of Subcom-
mittee B09.04 on Bearings.
Current edition approved April 1, 2021. Published May 2021. Originally For referenced ASTM standards, visit the ASTM website, www.astm.org, or
approved in 1966. Last previous edition approved in 2017 as B438– 17. DOI: contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
10.1520/B0438-21. Standards volume information, refer to the standard’s Document Summary page on
Machine Design Magazine, Vol 54, #14, June 17, 1982, pp. 130-142. 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
B438−21
E29Practice for Using Significant Digits in Test Data to
CTG-1004-K10
CTG-1004-K15
Determine Conformance with Specifications
E1019Test Methods for Determination of Carbon, Sulfur,
4.2.4 Prefix CTG-MOD—Bronze-Lead-Graphite (Military
Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Grade):
Alloys by Various Combustion and Inert Gas Fusion
CTG-1001-K23-MOD
Techniques
4.2.5 Prefix CFTG—Bronze (Diluted):
2.2 MPIF Standard:
CFTG-3806-K14
MPIF Standard 35 Materials Standards for PM Self-
CFTG-3806-K22
Lubricating Bearings
5. Ordering Information
2.3 ISO Standards:
5.1 Purchase orders or contracts for bronze-base, oil-
ISO 2795Plain Bearings Made from Sintered Material—
impregnated bearings covered by this purchasing specification
Dimensions and Tolerances
shall include the following information:
ISO 5755Sintered Metal Materials - Specifications
5.1.1 A copy of the bearing print showing dimensions and
2.4 Government Standards:
tolerances (Section 10),
MIL-PRF-6085Lubricating Oil: Instrument, Aircraft, Low
5.1.2 Reference to this ASTM Standard, including date of
Volatility
issue,
MIL-PRF-17331Lubrication Oil, Steam Turbine and Gear,
5.1.3 Identification of bearing material by the PM Material
Moderate Service
Designation Code (Section 4.2),
QPL-6085Lubricating Oil Instrument, Aircraft, Low Vola-
5.1.4 Request for Certification and Test Report documents,
tility
if required (Section 16),
QPL-17331Lubricating Oil, SteamTurbine and Gear, Mod-
5.1.5 Type and grade of special lubricating oil, if required
erate Service
(Section 6.2 or S2.2),
5.1.6 Instructionsforspecialpackaging,ifrequired(Section
3. Terminology
17).
3.1 Definitions—The definitions of the terms used in this
5.1.7 Chemicalcompositionlimits(Sections7.2and13.2)if
specification are found in Terminology B243. Additional de-
required,
scriptive information is available under “General Information
5.1.8 Sampling lot size (Section 12) if required,
on PM” on the ASTM B09 web page.
5.1.9 Testing procedure and strength requirement for the
flanges of flanged oil-impregnated bearings (Section 13.4.1.2)
4. Classification
if required,
4.1 This specification uses the established three-part alpha-
5.1.10 Bearing breaking load (Section 13.4.2) if required.
numeric PM Material Designation Code to identify the non-
5.2 Thoseadditionalgovernmentrequirementsnecessaryon
ferrous materials used for self-lubricating PM bearings. The
orders for military bearings are prescribed in the Supplemen-
complete explanation of this classification system is presented
tary Requirements section.
in Annex A1.
6. Materials and Manufacture
4.2 The following standard oil-impregnated bronze-base
bearing material compositions are contained in this specifica-
6.1 Porous Metallic Bearing:
tion:
6.1.1 Sintered bronze-base bearings shall be produced by
4.2.1 Prefix CT—Bronze (Low Graphite):
firstcompactingpre-alloyedbronzeorelementalcopperandtin
powders and any other additives appropriate for the composi-
CT-1000-K19
CT-1000-K26
tion to the proper density and bearing configuration.
CT-1000-K37
6.1.2 The green bearings shall then be sintered in a protec-
CT-1000-K40
tiveatmospherefurnaceforatimeandtemperaturerelationship
4.2.2 Prefix CTG—Bronze-Graphite (Medium Graphite):
that will produce the required sintered bronze-base PM mate-
CTG-1001-K17
rial.
CTG-1001-K23
6.1.3 After sintering, the bronze-base bearings are normally
CTG-1001-K30
CTG-1001-K34 sized to achieve the density, dimensional characteristics,
concentricity, and surface finish required of the metallic
4.2.3 Prefix CTG—Bronze (High Graphite):
bearing.
6.2 Oil for Operating Lubrication:
Available from Metal Powder Industries Federation (MPIF), 105 College Rd.
6.2.1 The surface-connected porosity in the bearings shall
East, Princeton, NJ 08540-6692, http://www.mpif.org.
5 be filled to the required volume with lubricating oil, either by
Available from International Organization for Standardization (ISO), ISO
an extended soaking in the hot oil or preferably by a vacuum
Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
Switzerland, https://www.iso.org.
impregnation operation.
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
6.2.2 Amediumviscositypetroleumoilisnormallyusedfor
Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://
most bearing applications, but extreme operating conditions
dodssp.daps.dla.mil. Electronic copies of military specifications may be obtained
from http://assist.daps.dla.mil/. such as elevated temperatures, intermittent rotation, extremely
B438−21
TABLE 1 Specifications for Bronze-Base Materials used in PM Bearings
Physical Mechanical
Chemical Requirements
Requirements Requirements
Radial Crushing
Material Designation Code Strength, K
Graphitic All
Copper Tin Lead Iron
Carbon Others
Impregnated Content
mass % mass % mass % mass %
mass % mass %
Density Oil 10 psi (MPa)
g/cm vol %
Bronze (Low Graphite)
A,G
CT-1000-K19 bal 9.5-10.5 — 0.3 max 1.0 max 1.0 max 6.0-6.4 24 min 19 min (130 min)
G
CT-1000-K26 bal 9.5-10.5 — 0.3 max 1.0 max 1.0 max 6.4-6.8 19 min 26 min (180 min)
G
CT-1000-K37 bal 9.5-10.5 — 0.3 max 1.0 max 1.0 max 6.8-7.2 12 min 37 min (260 min)
G
CT-1000-K40 bal 9.5-10.5 — 0.3 max 1.0 max 1.0 max 7.2-7.6 9 min 40 min (280 min)
Bronze (Medium Graphite)
B,G
CTG-1001-K17 bal 9.5-10.5 — 0.5-1.8 1.0 max 1.0 max 6.0-6.4 22 min 17 min (120 min)
G
CTG-1001-K23 bal 9.5-10.5 — 0.5-1.8 1.0 max 1.0 max 6.4-6.8 17 min 23 min (160 min)
G
CTG-1001-K30 bal 9.5-10.5 — 0.5-1.8 1.0 max 1.0 max 6.8.7.2 9 min 30 min (210 min)
G
CTG-1001-K34 bal 9.5-10.5 — 0.5-1.8 1.0 max 1.0 max 7.2-7.6 7 min 34 min (230 min)
Bronze (High Graphite)
G,I
CTG-1004-K10 bal 9.2-10.2 — 2.5-5.0 1.0 max 1.0 max 5.8-6.2 11 min 10 min (70 min)
C,G
CTG-1004-K15 bal 9.2-10.2 — 2.5-5.0 1.0 max 1.0 max 6.2-6.6 15 min (100 min)
Bronze-Lead-Graphite (Military Grade)
D G
CTG-1001-K23-MOD bal 9.5-10.5 2.0-4.0 0.5-1.75 1.0 max 0.5 max 6.4-6.8 17 min 23 min (160 min)
Bronze (Diluted)
E F H
CFTG-3806-K14 bal 5.5-6.5 — 36.0-40.0 2.0 max 5.6-6.0 22 min 14-35 (100-240)
E F H
CFTG-3806-K22 bal 5.5-6.5 — 36.0-40.0 2.0 max 6.0-6.4 17 min 22-50 (150-340)
A 3
For an oil content of 27 % min, density range will be 5.8-6.2 g/cm and radial crushing strength will be 15 000 psi (100 MPa) minimum.
B 3
For an oil content of 25 % min, density range will be 5.8-6.2 g/cm and radial crushing strength will be 13 000 psi (90 MPa) minimum.
C 3 3
At maximum graphite (5 %) and density (6.6 g/cm ), this material will contain only a trace of oil. At 3 % graphite and 6.2-6.6 g/cm density, it will contain 8 vol % (min.)
of oil.
D
Additional chemical requirements are: Zinc–0.75 % max, Nickel–0.35 % max, Antimony–0.25 % max.
E
Graphitic carbon content is typically 0.5-1.3 %; total carbon shall be 0.5-1.3 %.
F
The iron portion may contain 0.5 % max metallurgically combined carbon.
G
Minimum oil content will decrease with increasing density. Those shown are valid at the upper-limit of the density given.
H
These data are based on material in the finished condition.
I
At 3 % graphite, it will contain 14 % min oil content.
lowspeeds,orheavyloadsmayrequireasyntheticlubricantor 8.2 Impregnation Effıciency—A minimum of 90% of the
an oil with a different viscosity. surface-connected porosity in the as-received bearings shall be
6.2.3 Unless otherwise specified by the purchaser, a high- impregnated with lubricating oil.
grade turbine oil with antifoaming additives and containing
8.3 Impregnated Density—The density of the sample
corrosion and oxidation inhibitors, having a kinematic viscos-
bearings, when fully impregnated with lubricating oil, shall
-6 -6 2
ity of 280 to 500 SSU [(60 × 10 to110×10 m /s), (60 to
meet the requirements prescribed in Table 1 for each bearing
110 cSt)] at 100 °F (38 °C) is normally used as a general
material.
purpose lubricating oil.
9. Mechanical Properties
7. Chemical Composition
9.1 Radial Crushing Strength—The radial crushing strength
7.1 Chemical Composition Specifications—Each bronze-
of the oil-impregnated bearing material determined on a plain
base PM bearing material shall conform to the chemical
sleeve bearing or a test specimen prepared from a flange or
requirementsprescribedinTable1whendeterminedonaclean
spherical bearing shall meet the minimum and maximum (if
test sample from oil-free bearings.
required) strength values listed in Table 1.
7.2 Limits on Nonspecified Elements—By agreement be-
10. Dimensions, Mass, and Permissible Variations
tween the purchaser and the producer, limits may be estab-
10.1 This standard is applicable to bronze-base PM sleeve
lished and chemical analyses required for elements or com-
pounds not specified in Table 1. and flange bearings havinga4to1 maximum length to inside
diameter ratio and a 24 to 1 maximum length to wall thickness
8. Physical Properties ratio.
8.1 Oil Content—For each bearing material, the oil content 10.2 Sleeve, flange, thrust, and spherical PM bearings
of the as-received bearing shall not be less than the minimum covered by this specification are illustrated by Figs. 1-4. Most
percentage listed in Table 1. PM bearings are small and weigh less than one-quarter pound
B438−21
11. Workmanship, Finish, and Appearance
11.1 Thebearingsshouldhaveamattesurfaceandnotshow
oxidation. The surfaces of sized bearings should have a
smooth, bright finish.
11.2 When cut or fractured, the exposed surface of the
bearings should exhibit a uniform visual appearance.
11.3 If metallographic examination is performed to deter-
mine degree of sintering, it should be done at 200-400X
FIG. 1Standard Sleeve Bearing
magnification. In 90Cu-10Sn bronze bearings, the microstruc-
ture should be alpha bronze with no silver-gray tin-rich copper
compounds and with a minimum of reddish copper-rich areas.
The structure should have a very minimum number of original
particle boundaries. Diluted bronze material should show a
bronze phase with no visible free tin, dispersed throughout an
iron matrix.
11.4 To verify that oil is present, heat the bearing to about
300°F(150°C)for5min.Ifoilispresent,thebearingsurfaces
exhibit beads of oil being exuded from the pores.
11.5 Whenbearingsareorderedasbeing“dry-to-the-touch”
FIG. 2Standard Flange Bearing
to allow automated handling by the purchaser, the excess
surfaceoilisnormallyremovedbyacentrifugaloperation.Itis
important that the Oil Content test (13.3.2) be performed after
the surface drying treatment to make certain that the required
volume of lubricating oil is present.
12. Sampling
12.1 Lot—Unless otherwise specified, a lot shall be defined
as a specific quantity of bearings manufactured under
FIG. 3Standard Thrust Bearing
traceable, controlled conditions as agreed to between the
producer and purchaser (Terminology B243).
12.2 Sampling Plan—The number of sample bearings,
agreed to between the producer and the purchaser, to be used
for inspections shall be taken randomly from locations
throughout the lot.
13. Test Methods
13.1 Dimensional Measurements:
13.1.1 Using suitable measuring equipment, the inside di-
FIG. 4Standard Spherical Bearing
ameter of the bearings shall be measured to the nearest 0.0001
in. (0.0025 mm). The other bearing dimensions only require
instrumentation capable of measuring to the tolerances speci-
fied on the bearing drawing.
(~100 g) but they can be produced in sizes that will accom-
13.2 Chemical Analysis:
modate shafts up to approximately 8 in. (200 mm) in diameter.
13.2.1 Oil Extraction—Bearings must be dry and free of oil
10.3 Permissible variations in dimensions shall be within
before running chemical tests. To remove oil, a Soxhlet
the tolerance limits shown on the bearing print accompanying
Apparatus as specified in Test Method B963 may be used.
the order or shall be within the limits specified in the purchase
However, upon agreement between purchaser and producer, a
order or contract. Dimensional tolerances of bearings for
low-temperature furnace treatment [1000 to 1200 °F (540 to
military or government applications shall meet the require-
650 °C)] with a flowing nitrogen or inert atmosphere may be
ments specified in the Supplementary Requirements section.
used to volatilize any lubricant that may be present.
10.4 Recommended commercial tolerances for bronze-base
13.2.2 Metallic Elements—The chemical analysis of metal-
PM bearings are referenced throughout the tables in Appendix
lic elements shall be performed on an oil-free sample in
X2.
accordance with the test methods prescribed in Volume 03.05
10.5 Chamfersof30-45°aregenerallyusedonPMbearings ofthe Annual Book ofASTM Standardsorbyanotherapproved
to break the corners. method agreed upon between the producer and the purchaser.
B438−21
13.2.3 Combined Carbon—To determine the amount of 13.4.2 BearingBreakingLoad—Ifagreedtobytheproducer
carbon metallurgically combined with the iron in the diluted andthepurchaser,anacceptancespecificationfortheminimum
bronze materials, a metallographic estimate may be made. (maximum)bearingbreakingload, P (P )inlbf(N),may
min, max
be established for any specific standard oil-impregnated bear-
13.2.4 Graphitic Carbon—Determine the total carbon con-
ing. This simplifies acceptance testing because the decision is
tent in accordance withTest Method E1019 with the exception
now based solely upon reading the output of the testing
that a sample as small as 0.25 g may be used upon agreement
machine without a need for further calculations. This accep-
between purchaser and producer.With the exception of diluted
tanceprocedurecanbeveryusefulwhenevaluatingmultipleor
bronze, the graphitic carbon provides an estimate of the total
repeat shipments of the same bearing.
carbon. For diluted bronze, the graphitic carbon is approxi-
mately equal to the total carbon minus the combined carbon as
13.4.2.1 The minimum (maximum) breaking load,
determined in 13.2.3.
P (P )requiredforacceptanceofanyspecificplainsleeve
min, max
orthrustbearingiscalculatedusingthebreakingloadformula:
13.3 Physical Properties:
K 3L 3t
13.3.1 Oil Content—The oil content of the as-received
P ~P ! 5 (1)
min, max
D 2 t
bearing shall be determined following the procedure for
As-Received Oil Content in Test Method B963.
where:
13.3.2 Impregnation Effıciency—The efficiency of the oil-
P (P = minimum (maximum) bearing breaking load,
min, max)
impregnation process in volume percent units shall be calcu-
lbf (N),
lated following the procedure for Oil-Impregnation Effıciency
K = minimum (maximum) radial crushing
in Test Method B963.
strength, psi (MPa),
13.3.3 Impregnated Density—The impregnated density of
L = length of bearing, in. (mm),
the sample bearings in g/cm units, measured after they have
t = wall thickness, [t=(D – d) / 2], in. (mm),
been fully impregnated, shall be determined following the D = outside diameter, in. (mm), and
procedure for Determination of Impregnated Density in Test d = inside diameter, in. (mm).
Method B962.
13.4.2.2 Use the minimum (maximum) radial crushing
13.4 Mechanical Properties: strength value specified for the oil-impregnated bearing mate-
rial from Table 1 for K, use the actual D, d and L dimensions
13.4.1 Radial Crushing Strength—Radial crushing strength
of the as-received bearing and solve for P (P ). This
in psi (MPa) is the mechanical property by which the strength
min, max
calculated value will be the minimum (maximum) acceptable
of oil-impregnated PM bearing material is characterized and
breaking load for that specific plain bearing. Using the allow-
evaluated. It is determined by breaking plain thin-walled
able print dimensions that minimize (maximize) the volume of
bearingsorhollowcylindricaltestspecimensunderdiametrical
loading, following the procedures described in Test Method the bearing for the calculations will result in a breaking load
specification(s)thatwillbeapplicabletoanylotofthatspecific
B939,andcalculatingtheradialcrushingstrengthaccordingto
the material strength formula contained therein. bearing.
13.4.1.1 Plain sleeve bearings and thrust bearings are tested 13.4.2.3 The minimum (maximum) acceptable breaking
in the oil-impregnated condition. For acceptance, the radial load for a specific flanged bearing shall be calculated by first
crushing strength, determined on the test bearings, shall not be cuttingofftheflangeandmeasuringtheD,d,andLofthebody.
less than the minimum nor more than the maximum (if Then, using the minimum (maximum) radial crushing strength
applicable) strength specification values listed in Table 1 for
fortheoil-impregnatedbearingmaterialinTable1for Kinthe
the bearing material.
breaking load formula and the measured dimensions of the
body, a P (P ) value may be calculated. This will be the
13.4.1.2 Flangedoil-impregnatedbearingsshallbetestedby
min, max
minimum (maximum) bearing breaking load required for the
cutting off the flange and crushing the body as a plain sleeve
bearing. For acceptance, the radial crushing strength so deter- body of that specific flanged bearing. The test procedure and
breaking load requirements for the flange shall be a matter of
mined shall meet the minimum and maximum (if applicable)
material strength requirements prescribed in Table 1. The agreement between purchaser and producer.
testing procedure and material strength requirements of the
13.4.2.4 Foracceptancetestingofwholesphericalbearings,
flange shall be a matter of agreement between producer and
a minimum (maximum) bearing breaking load specification,
purchaser.
P (P ) may be established on a specific whole spherical
min, max
13.4.1.3 To evaluate spherical, or bearings of other oil-impregnatedbearing.First,theradialcrushingstrength, K ,
a
configuration, a number of sample bearings from the lot shall is determined on that specific spherical bearing machined to a
first be machined to a right circular cylinder, measured, and plain cylinder as in 13.4.1.3. Second, whole spherical bearings
then crushed to determine the radial crushing strength of the fromthesamelotarecrushed,keepingtheiraxeshorizontal,to
oil-impregnated bearing material. This value shall not be less determine the breaking load of the whole bearing. Then, using
than the minimum nor more than the maximum (if applicable) the correlation formula, the specifications for the breaking
radial crushing strength specified in Table 1 for the material in load, P of that whole spherical bearing are calculated as
a,
the sample bearings. follows:
B438−21
K 3P 14.3 Upon receipt of the shipment, the purchaser may
a
P ~P ! 5 (2)
min, max
K conduct whatever quality control inspections that he feels are
a
necessary to confirm compliance to the purchasing require-
where:
ments.
P (P ) = specification for the minimum (maximum)
min, max
15. Rejection and Rehearing
bearing breaking load of a specific whole
spherical bearing, lbf (N),
15.1 Rejection based on tests made in accordance with this
K = radial crushing strength of the machined test
a
specificationshallbereportedinwritingtotheproducerwithin
spherical bearings according to 13.4.1.3, psi
30 days of receipt of the shipment; the rejected bearings,
(MPa),
however, shall not be returned or disposed of without written
K = minimum(maximum)radialcrushingstrength
authorization from the producer.
for the bearing material, (Table 1), psi (MPa),
15.2 Incaseofdissatisfactionwiththetestresults,eitherthe
and
purchaser or producer may make a claim for rehearing.
P = breakingloadofwholetestsphericalbearings,
a
lbf (N).
16. Certification and Test Report
13.5 Conformance:
16.1 The purchaser may require in the purchase order or
13.5.1 Dimensional Measurements—For purposes of deter-
contract that the producer shall supply a Certificate of Com-
mining conformance with the dimensional specifications, the
pliance stating that the bearings were produced and tested in
tolerance limits specified on the bearing print are considered
accordance with this specification and met all requirements.
absolute limits as defined in Practice E29.
16.2 In addition, when required by the purchase order or
13.5.2 Chemical, Physical, Mechanical Test Results—For
contract, the producer shall furnish a Test Report that lists the
purposes of determining conformance with these
results of the chemical, physical, mechanical, and functional
specifications, an observed value or calculated value shall be
tests performed on the sample bearings.
rounded“tothenearestunit”inthelastright-handdigitusedin
expressing the specification limit, in accordance with the 16.3 Unless otherwise agreed upon between the purchaser
rounding-off method of Practice E29. and the producer, the Certificate of Compliance, the Test
13.5.3 Measurement Uncertainty—The precision and bias Report, or both will be transmitted by electronic service.
of the test result values shall be considered by the purchaser
17. Packaging
and producer in determining conformance.
17.1 Unlessspecificpackagingrequirementsareincludedin
thepurchaseorderorcontract,thefinishedoil-impregnatedPM
14. Inspection
bearings shall be packaged and shipped in containers of a
14.1 Theproducerhastheprimaryresponsibilitytoconduct
nonabsorbent material to prevent loss of lubricating oil.
the necessary measurements and tests to ensure that the
bearings meet the requirements of the purchase order or 18. Keywords
contract and this specification before they are shipped to the
18.1 bearing breaking load; bronze bearings; impregnated
purchaser.
density; interconnected porosity; oil content; oil-impregnated
14.2 Provided the producer notifies the purchaser, all or a bearings; open porosity; PM bearings; porous metallic bear-
portionoftherequiredconformancetestsmaybecontractedto ings; PV Factor; PV Limit; radial crushing strength; self-
a qualified third party. lubricating bearings
SUPPLEMENTARY REQUIREMENTS
MILITARY BEARINGS, SINTERED BRONZE, OIL-IMPREGNATED
The following supplementary requirements shall apply to purchase orders or contracts from all
agencies of the United States Government or where specified by a purchaser as part of the purchase
order or contract with a government agency.
S1. Introduction industry accepted material designation codes from MPIF
Standard 35 (Bearings) (see Table A2.1 for conversion infor-
S1.1 The B438 purchasing specification incorporates and
mation). In addition to meeting the primary specifications, the
updates the applicable portions of specifications from four
purchaser of bearings for military or government applications
now-cancelled military standards, bringing the military re-
must comply with additional specific requirements. This
quirements into alignment with the rest of this consensus
Supplementary Requirements section details those additional
specification. The type and grade designations from four
governmental requirements.
now-cancelled military standards have been converted to the
B438−21
S1.2 The bearings referred to within this specification are material, lot number, lot size, dimensions, date of testing, test
not intended for reaming on assembly. method, individual test results, and specification requirements.
S2.6 Records—Records of examination and tests performed
S1.3 The bearings referred to within this specification are
byorforthecontractorshallbemaintainedandmadeavailable
not recommended for military airframe applications.
totheGovernmentbythecontractorforaperiodofthreeyears
after delivery of the products and associate material.
S2. Government Requirements
S2.7 Inspection—Unless otherwise specified, the producer
S2.1 Chemical, Physical and Mechanical Requirements—
is responsible for testing. The producer may use their own or
RefertoSection1andTable1forthespecificationsforbearing
any other suitable facility for the performance of testing and
materials that shall conform to material designation codes
inspection, unless an exception is stated. The Government
CTG-1001-K23 (sleeve, flange and thrust washer) or CTG-
reservestherighttoperformaninspectionassetforthhereinto
1001-K23-MOD (sleeve and flange only).The contractor shall
assure supplies and sources conform to the prescribed require-
furnishachemicalcompositionanalysisonanoil-freebasisfor
ments.
each lot showing the weight percentage for each element as
S2.8 Packaging—Special packaging and marking require-
specified in Table 1. Bearings shall conform to this specifica-
ments shall be included in the contract or will conform to
tion.
Section 17, Packaging.
S2.1.1 Compressive Yield Strength—The yield strength in
S2.9 Requirements—All requirements shall be as specified
compression shall be 11000 psi (75 MPa) (minimum) for 0.1
herein. Referenced military standard specification sheets shall
percent permanent offset in accordance with section X3.2.1.
take precedence unless otherwise specified in the purchase
S2.1.2 Surface Finish—For thrust washer bearings, all sur- order or contract.
faces shall have a surface finish of 125 µin. maximum, except
asnotedonaprintordrawing.Surfacefinishshallbemeasured S3. Ordering Information
in accordance with Test Method B946.
S3.1 Purchase Order or Contract—Ordering information
S2.2 Oil-Impregnation—High-grade non-gumming petro-
shall be in accordance with Section 5 of this specification and
leum lubricants purchased in accordance with the applicable
shall also include:
Qualified Products Lists (QPLs), such as MIL-PRF-17331
S3.1.1 PINfromS3.3,TableS3.1,TableS3.2orTableS3.3,
(Military Symbol 2190–TEP, NATO Code O-250 and QPL-
S3.1.2 National Stock Number (NSN),
17331) for sleeve and flange bearings and MIL-PRF-6085
S3.1.3 Quantity,
(MilitarySymbolOAI,NATOCodeNo.0-147andQPL-6085)
S3.1.4 Requirements for testing including FAT,
for thrust washer bearings, or as specified on referenced
S3.1.15 COQC if required, and
military standard specification sheets shall be used to impreg-
S3.1.6 Packagingrequirements,ifdifferentfromSection17.
nate the bearings.
S3.2 PIN—The military PIN shall consist of the letters and
S2.3 First Article Tests (FAT)—When specified in the
numbers representing the old MS documents and taken from
contract, FATs shall be performed on a number of samples
the titles of Table S3.1 (for sleeve), Table S3.2 (for flange) or
(four minimum). The tests performed shall conform to 12.2,
TableS3.3(forthrustwasher),adashnumberfromeitherTable
Sampling Plan and shall include testing for interconnected
S3.1 (for sleeve), Table S3.2 (for flange) or Table S3.3 (for
porosity. Testing shall be as specified within this specification,
thrust washer), and a suffix ofYor Z representing the material
Test Method B963 or in another document as specified in the
designation code.
contract. Any defect or failure shall be cause for rejection of
Example:MS17796 2104 2Y
the lot. Waivers for minor defects may be addressed to the
contracting officer.
where:
Note—In order to perform all the tests on a single bearing,
MS17796 = the number from Table S3.1 or Table S3.2 or
the following order of tests is suggested: dimensional, impreg-
Table S3.3 representing the old MS document,
nated density, interconnected porosity, oil content, oil 104 = Dash number, from Table S3.1 or Table S3.2 or
exudation, radial crushing strength and chemical analysis. Table S3.3,
Y = Material Designation Code:
S2.4 Oil Exudation Test—During the test period for oil
Y = CTG-1001-K23 and
exudation,beadsshallexudefromthebearingsurface.Lackof
Z = CTG-1001-K23 MOD
appreciable sweating of the lubricant on the bearing surface
will be cause for rejection (see 11.4).
Note—The MS17796–104–Y part identification number
S2.5 COQC—When procured from a dealer or distributor (PIN) equates to the old MS17796-104 designation where the
versustheactualproducer,acertificateofqualityconformance MS17796 represented the military standard number for flange
(COQC) supplied by the producer of the bearing may be bearings (sleeve and thrust bearings are described in MS17795
furnished in lieu of actual performance of such testing by the and MS21783 respectively), the 104 was the dash number; as
dealerordistributor,providedlotidentityistraceable,hasbeen forthesuffixY,itisnew;inMS17796,thematerialdesignation
maintained and can be demonstrated to the Government. The code was called out separately as a Grade and Type and was
certificate shall include the name of the dealer or distributor, not a part of the PIN but was part of the required ordering
dealer or distributor number, name of producer, national stock information. The dash numbers themselves remain unchanged
number (NSN), item identification, name of the component or from those in MS17795, MS17796 and MS21783.
B438−21
TABLE S3.1 MS17795 Bronze Sleeve Bearings—Dimensions and
Dash Numbers
Static Inner Outer
Dash Length, Nominal
Capacity Diameter, Diameter,
No. L (in.) ID (in.)
(lb) d (in.) D (in.)
3 1
197 ⁄32 ⁄8 0.127 0.1905
1 1
2 129 ⁄8 ⁄8 0.127 0.1905
3 1
3 194 ⁄16 ⁄8 0.127 0.1905
1 1
4 258 ⁄4 ⁄8 0.127 0.1905
1 1
5 129 ⁄8 ⁄8 0.127 0.253
3 1
6 194 ⁄16 ⁄8 0.127 0.253
1 1
7 258 ⁄4 ⁄8 0.127 0.253
5 1
8 323 ⁄16 ⁄8 0.127 0.253
1 3
9 193 ⁄8 ⁄16 0.1895 0.253
3 3
10 290 ⁄16 ⁄16 0.1895 0.253
1 3
11 387 ⁄4 ⁄16 0.1895 0.253
5 3
12 483 ⁄16 ⁄16 0.1895 0.253
3 3
13 580 ⁄8 ⁄16 0.1895 0.253
7 3
14 677 ⁄16 ⁄16 0.1895 0.253
3 3
15 290 ⁄16 ⁄16 0.1895 0.3155
1 3
16 387 ⁄4 ⁄16 0.1895 0.3155
5 3
17 483 ⁄16 ⁄16 0.1895 0.3155
3 3
18 580 ⁄8 ⁄16 0.1895 0.3155
7 3
19 677 ⁄16 ⁄16 0.1895 0.3155
1 3
20 774 ⁄2 ⁄16 0.1895 0.3155
3 1
21 386 ⁄16 ⁄4 0.252 0.378
1 1
22 516 ⁄4 ⁄4 0.252 0.378
5 1
23 645 ⁄16 ⁄4 0.252 0.378
3 1
24 773 ⁄8 ⁄4 0.252 0.378
7 1
25 902 ⁄16 ⁄4 0.252 0.378
1 1
26 1031 ⁄2 ⁄4 0.252 0.378
5 1
27 1289 ⁄8 ⁄4 0.252 0.378
3 1
28 386 ⁄16 ⁄4 0.252 0.4405
1 1
29 516 ⁄4 ⁄4 0.252 0.4405
5 1
30 645 ⁄16 ⁄4 0.252 0.4405
3 1
31 773 ⁄8 ⁄4 0.252 0.4405
7 1
32 902 ⁄16 ⁄4 0.252 0.4405
1 1
33 1031 ⁄2 ⁄4 0.252 0.4405
5 1
34 1289 ⁄8 ⁄4 0.252 0.4405
3 1
35 1547 ⁄4 ⁄4 0.252 0.4405
1 5
36 645 ⁄4 ⁄16 0.3145 0.4405
5 5
37 806 ⁄16 ⁄16 0.3145 0.4405
3 5
38 967 ⁄8 ⁄16 0.3145 0.4405
7 5
39 1128 ⁄16 ⁄16 0.3145 0.4405
1 5
40 1289 ⁄2 ⁄16 0.3145 0.4405
5 5
41 1611 ⁄8 ⁄16 0.3145 0.4405
3 5
42 1934 ⁄4 ⁄16 0.3145 0.4405
1 3
43 773 ⁄4 ⁄8 0.377 0.503
5 3
44 967 ⁄16 ⁄8 0.377 0.503
3 3
45 1160 ⁄8 ⁄8 0.377 0.503
7 3
46 1354 ⁄16 ⁄8 0.377 0.503
1 3
47 1547 ⁄2 ⁄8 0.377 0.503
5 3
48 1934 ⁄8 ⁄8 0.377 0.503
3 3
49 2320 ⁄4 ⁄8 0.377 0.503
7 3
50 2707 ⁄8 ⁄8 0.377 0.503
51 3094 1 ⁄8 0.377 0.503
1 3
52 773 ⁄4 ⁄8 0.377 0.628
5 3
53 967 ⁄16 ⁄8 0.377 0.628
3 3
54 1160 ⁄8 ⁄8 0.377 0.628
7 3
55 1354 ⁄16 ⁄8 0.377 0.628
1 3
56 1547 ⁄2 ⁄8 0.377 0.628
5 3
57 1934 ⁄8 ⁄8 0.377 0.628
3 3
58 2320 ⁄4 ⁄8 0.377 0.628
7 3
59 2707 ⁄8 ⁄8 0.377 0.628
60 3094 1 ⁄8 0.377 0.628
1 3
61 3867 1- ⁄4 ⁄8 0.377 0.628
3 7
62 1354 ⁄8 ⁄16 0.439 0.565
7 7
63 1579 ⁄16 ⁄16 0.439 0.565
1 7
64 1805 ⁄2 ⁄16 0.439 0.565
5 7
65 2256 ⁄8 ⁄16 0.439 0.565
3 7
66 2707 ⁄4 ⁄16 0.439 0.565
7 7
67 3158 ⁄8 ⁄16 0.439 0.565
68 3609 1 ⁄16 0.439 0.565
1 7
69 4512 1- ⁄4 ⁄16 0.439 0.565
3 1
70 1547 ⁄8 ⁄2 0.502 0.628
7 1
71 1805 ⁄16 ⁄2 0.502 0.628
1 1
72 2063 ⁄2 ⁄2 0.502 0.628
B438−21
TABLE Continued
Static Inner Outer
Dash Length, Nominal
Capacity Diameter, Diameter,
No. L (in.) ID (in.)
(lb) d (in.) D (in.)
5 1
73 2578 ⁄8 ⁄2 0.502 0.628
3 1
74 3094 ⁄4 ⁄2 0.502 0.628
7 1
75 3609 ⁄8 ⁄2 0.502 0.628
76 4125 1 ⁄2 0.502 0.628
1 1
77 5156 1- ⁄4 ⁄2 0.502 0.628
3 1
78 1547 ⁄8 ⁄2 0.502 0.753
1 1
79 2063 ⁄2 ⁄2 0.502 0.753
5 1
80 2578 ⁄8 ⁄2 0.502 0.753
3 1
81 3094 ⁄4 ⁄2 0.502 0.753
7 1
82 3609 ⁄8 ⁄2 0.502 0.753
83 4125 1 ⁄2 0.502 0.753
1 1
84 5156 1- ⁄4 ⁄2 0.502 0.753
1 1
85 6188 1- ⁄2 ⁄2 0.502 0.753
1 9
86 2320 ⁄2 ⁄16 0.565 0.695
5 9
87 2900 ⁄8 ⁄16 0.565 0.695
3 9
88 3480 ⁄4 ⁄16 0.565 0.695
7 9
89 4061 ⁄8 ⁄16 0.565 0.695
90 4641 1 ⁄16 0.565 0.695
1 9
91 5801 1- ⁄4 ⁄16 0.565 0.695
1 9
92 6961 1- ⁄2 ⁄16 0.565 0.695
1 5
93 2578 ⁄2 ⁄8 0.627 0.753
5 5
94 3223 ⁄8 ⁄8 0.627 0.753
3 5
95 3867 ⁄4 ⁄8 0.627 0.753
7 5
96 4518 ⁄8 ⁄8 0.627 0.753
97 5156 1 ⁄8 0.627 0.753
1 5
98 6445 1- ⁄4 ⁄8 0.627 0.753
1 5
99 7734 1- ⁄2 ⁄8 0.627 0.753
1 5
100 2578 ⁄2 ⁄8 0.627 0.879
5 5
101 3223 ⁄8 ⁄8 0.627 0.879
3 5
102 3867 ⁄4 ⁄8 0.627 0.879
7 5
103 4518 ⁄8 ⁄8 0.627 0.879
104 5156 1 ⁄8 0.627 0.879
1 5
105 6445 1- ⁄4 ⁄8 0.627 0.879
1 5
106 7734 1- ⁄2 ⁄8 0.627 0.879
3 5
107 9023 1- ⁄4 ⁄8 0.627 0.879
1 3
108 3094 ⁄2 ⁄4 0.752 0.879
5 3
109 3867 ⁄8 ⁄4 0.752 0.879
3 3
110 4640 ⁄4 ⁄4 0.752 0.879
7 3
111 5414 ⁄8 ⁄4 0.752 0.879
112 6188 1 ⁄4 0.752 0.879
1 3
113 7734 1- ⁄4 ⁄4 0.752 0.879
1 3
114 9281 1- ⁄2 ⁄4 0.752 0.879
3 3
115 10828 1- ⁄4 ⁄4 0.752 0.879
1 3
116 3094 ⁄2 ⁄4 0.752 1.004
5 3
117 3867 ⁄8 ⁄4 0.752 1.004
3 3
118 4640 ⁄4 ⁄4 0.752 1.004
7 3
119 5414 ⁄8 ⁄4 0.752 1.004
120 6188 1 ⁄4 0.752 1.004
1 3
121 7734 1- ⁄4 ⁄4 0.752 1.004
1 3
122 9281 1- ⁄2 ⁄4 0.752 1.004
3 3
123 10828 1- ⁄4 ⁄4 0.752 1.004
124 12375 2 ⁄4 0.752 1.004
5 7
125 4512 ⁄8 ⁄8 0.877 1.004
3 7
126 5414 ⁄4 ⁄8 0.877 1.004
7 7
127 6316 ⁄8 ⁄8 0.877 1.004
128 7219 1 ⁄8 0.877 1.004
1 7
129 9023 1- ⁄4 ⁄8 0.877 1.004
1 7
130 10828 1- ⁄2 ⁄8 0.877 1.004
3 7
131 12633 1- ⁄4 ⁄8 0.877 1.004
132 6188 ⁄4 1 1.003 1.129
133 7219 ⁄8 1 1.003 1.129
134 8250 1 1 1.003 1.129
135 10313 1- ⁄4 1 1.003 1.129
136 12375 1- ⁄2 1 1.003 1.129
137 14438 1- ⁄4 1 1.003 1.129
138 16500 2 1 1.003 1.129
139 6188 ⁄4 1 1.003 1.254
140 7219 ⁄8 1 1.003 1.254
141 8250 1 1 1.003 1.254
142 10313 1- ⁄4 1 1.003 1.254
143 12375 1- ⁄2 1 1.003 1.254
144 14438 1- ⁄4 1 1.003 1.254
145 16500 2 1 1.003 1.254
B438−21
TABLE Continued
Static Inner Outer
Dash Length, Nominal
Capacity Diameter, Diameter,
No. L (in.) ID (in.)
(lb) d (in.) D (in.)
146 18563 2- ⁄4 1 1.003 1.254
147 20625 2- ⁄2 1 1.003 1.254
148 9281 1 1- ⁄8 1.128 1.378
1 1
149 11602 1- ⁄4 1- ⁄8 1.128 1.378
1 1
150 13922 1- ⁄2 1- ⁄8 1.128 1.378
3 1
151 16242 1- ⁄4 1- ⁄8 1.128 1.378
152 18563 2 1- ⁄8 1.128 1.378
1 1
153 20883 2- ⁄4 1- ⁄8 1.128 1.378
1 1
154 23203 2- ⁄2 1- ⁄8 1.128 1.378
155 10313 1 1- ⁄4 1.2535 1.504
1 1
156 12891 1- ⁄4 1- ⁄4 1.2535 1.504
1 1
157 15469 1- ⁄2 1- ⁄4 1.2535 1.504
3 1
158 18047 1- ⁄4 1- ⁄4 1.2535 1.504
159 20625 2 1- ⁄4 1.2535 1.504
1 1
160 23203 2- ⁄4 1- ⁄4 1.2535 1.504
1 1
161 25781 2- ⁄2 1- ⁄4 1.2535 1.504
3 1
162 28359 2- ⁄4 1- ⁄4 1.2535 1.504
163 30938 3 1- ⁄4 1.2535 1.504
164 11344 1 1- ⁄8 1.378 1.629
1 3
165 14180 1- ⁄4 1- ⁄8 1.378 1.629
1 3
166 17016 1- ⁄2 1- ⁄8 1.378 1.629
3 3
167 19852 1- ⁄4 1- ⁄8 1.378 1.629
168 22688 2 1- ⁄8 1.378 1.629
1 3
169 25523 2- ⁄4 1- ⁄8 1.378 1.629
1 3
170 28359 2- ⁄2 1- ⁄8 1.378 1.629
3 3
171 31195 2- ⁄4 1- ⁄8 1.378 1.629
172 34031 3 1- ⁄8 1.378 1.629
173 12375 1 1- ⁄2 1.504 1.755
1 1
174 15469 1- ⁄4 1- ⁄2 1.504 1.755
1 1
175 18563 1- ⁄2 1- ⁄2 1.504 1.755
3 1
176 21656 1- ⁄4 1- ⁄2 1.504 1.755
177 24750 2 1- ⁄2 1.504 1.755
1 1
178 27844 2- ⁄4 1- ⁄2 1.504 1.755
1 1
179 30938 2- ⁄2 1- ⁄2 1.504 1.755
3 1
180 34031 2- ⁄4 1- ⁄2 1.504 1.755
181 37125 3 1- ⁄2 1.504 1.755
1 3
182 21656 1- ⁄2 1- ⁄4 1.753 2.005
3 3
183 25266 1- ⁄4 1- ⁄4 1.753 2.005
184 28875 2 1- ⁄4 1.753 2.005
1 3
185 32484 2- ⁄4 1- ⁄4 1.753 2.005
1 3
186 36094 2- ⁄2 1- ⁄4 1.753 2.005
3 3
187 39703 2- ⁄4 1- ⁄4 1.753 2.005
188 43313 3 1- ⁄4 1.753 2.005
189 28875 1- ⁄4 2 2.004 2.38
190 33000 2 2 2.004 2.38
191 37125 2- ⁄4 2 2.004 2.38
192 41250 2- ⁄2 2 2.004 2.38
193 45375 2- ⁄4 2 2.004 2.38
194 49500 3 2 2.004 2.38
195 57750 3- ⁄2 2 2.004 2.38
196 66000 4 2 2.004 2.38
197 37125 2 2- ⁄4 2.254 2.631
1 1
198 46406 2- ⁄2 2- ⁄4 2.254 2.631
199 55688 3 2- ⁄4 2.254 2.631
1 1
200 64969 3- ⁄2 2- ⁄4 2.254 2.631
201 74250 4 2- ⁄4 2.254 2.631
202 41250 2 2- ⁄2 2.505 3.006
1 1
203 51563 2- ⁄2 2- ⁄2 2.505 3.006
204 61875 3 2- ⁄2 2.505 3.006
1 1
205 72188 3- ⁄2 2- ⁄2 2.505 3.006
206 82500 4 2- ⁄2 2.505 3.006
5 1
207 323 ⁄16 ⁄8 0.127 0.1905
3 1
208 387 ⁄8 ⁄8 0.127 0.1905
7 1
209 451 ⁄16 ⁄8 0.127 0.1905
1 1
210 516 ⁄2 ⁄8 0.127 0.1905
3 1
211 387 ⁄8 ⁄8 0.127 0.253
7 1
212 451 ⁄16 ⁄8 0.127 0.253
1 1
213 516 ⁄2 ⁄8 0.127 0.253
1 5
214 161 ⁄8 ⁄32 0.158 0.253
3 5
215 242 ⁄16 ⁄32 0.158 0.253
1 5
216 322 ⁄4 ⁄32 0.158 0.253
5 5
217 403 ⁄16 ⁄32 0.158 0.253
3 5
218 483 ⁄8 ⁄32 0.158 0.253
B438−21
TABLE Continued
Static Inner Outer
Dash Length, Nominal
Capacity Diameter, Diameter,
No. L (in.) ID (in.)
(lb) d (in.) D (in.)
7 5
219 564 ⁄16 ⁄32 0.158 0.253
1 5
220 645 ⁄2 ⁄32 0.158 0.253
1 3
221 774 ⁄2 ⁄16 0.1895 0.253
5 3
222 967 ⁄8 ⁄16 0.1895 0.253
3 3
223 1160 ⁄4 ⁄16 0.1895 0.253
5 3
224 967 ⁄8 ⁄16 0.1895 0.3155
3 3
225 1160 ⁄4 ⁄16 0.1895 0.3155
7 3
226 1354 ⁄8 ⁄16 0.1895 0.3155
227 1546 1 ⁄16 0.1895 0.3155
3 1
228 1547 ⁄4 ⁄4 0.252 0.378
7 1
229 1805 ⁄8 ⁄4 0.252 0.378
230 2063 1 ⁄4 0.252 0.378
1 1
231 2320 1- ⁄8 ⁄4 0.252 0.378
1 1
232 2578 1- ⁄4 ⁄4 0.252 0.378
7 1
233 1805 ⁄8 ⁄4 0.252 0.4405
234 2063 1 ⁄4 0.252 0.4405
1 1
235 2320 1- ⁄8 ⁄4 0.252 0.4405
1 1
236 2578 1- ⁄4 ⁄4 0.252 0.4405
1 1
237 3094 1- ⁄2 ⁄4 0.252 0.4405
7 5
238 2256 ⁄8 ⁄16 0.3145 0.4405
239 2578 1 ⁄16 0.3145 0.4405
1 5
240 2900 1- ⁄8 ⁄16 0.3145 0.4405
1 5
241 3223 1- ⁄4 ⁄16 0.3145 0.4405
1 5
242 3867 1- ⁄2 ⁄16 0.3145 0.4405
1 5
243 645 ⁄4 ⁄16 0.3145 0.503
5 5
244 806 ⁄16 ⁄16 0.3145 0.503
3 5
245 967 ⁄8 ⁄16 0.3145 0.503
7 5
246 1128 ⁄16 ⁄16 0.3145 0.503
1 5
247 1289 ⁄2 ⁄16 0.3145 0.503
5 5
248 1611 ⁄8 ⁄16 0.3145 0.503
3 5
249 1934 ⁄4 ⁄16 0.3145 0.503
7 5
250 2256 ⁄8 ⁄16 0.3145 0.503
251 2578 1 ⁄16 0.3145 0.503
1 5
252 2900 1- ⁄8 ⁄16 0.3145 0.503
1 5
253 3223 1- ⁄4 ⁄16 0.3145 0.503
1 5
254 3867 1- ⁄2 ⁄16 0.3145 0.503
1 3
255 3480 1- ⁄8 ⁄8 0.377 0.503
1 3
256 3867 1- ⁄4 ⁄8 0.377 0.503
1 3
257 4641 1- ⁄2 ⁄8 0.377 0.503
1 3
258 3480 1- ⁄8 ⁄8 0.377 0.628
1 7
259 4061 1- ⁄8 ⁄16 0.439 0.565
1 7
260 5414 1- ⁄2 ⁄16 0.439 0.565
1 1
261 4641 1- ⁄8 ⁄2 0.502 0.628
1 1
262 6188 1- ⁄2 ⁄2 0.502 0.628
5 1
263 6703 1- ⁄8 ⁄2 0.502 0.628
1 1
264 4641 1- ⁄8 ⁄2 0.502 0.753
5 1
265 6703 1- ⁄8 ⁄2 0.502 0.753
3 1
266 7219 1- ⁄4 ⁄2 0.502 0.753
7 1
267 8250 1- ⁄8 ⁄2 0.502 0.753
1 9
268 5221 1- ⁄8 ⁄16 0.565 0.695
1 5
269 5801 1- ⁄8 ⁄8 0.627 0.753
1 5
270 5801 1- ⁄8 ⁄8 0.627 0.879
5 5
271 8379 1- ⁄8 ⁄8 0.627 0.879
7 5
272 9668 1- ⁄8 ⁄8 0.627 0.879
273 10313 2 ⁄8 0.627 0.879
1 3
274 6961 1- ⁄8 ⁄4 0.752 0.879
5 3
275 10055 1- ⁄8 ⁄4 0.752 0.879
1 3
276 6961 1- ⁄8 ⁄4 0.752 1.004
5 3
277 10055 1- ⁄8 ⁄4 0.752 1.004
7 3
278 11602 1- ⁄8 ⁄4 0.752 1.004
1 3
279 13922 2- ⁄4 ⁄4 0.752 1.004
1 3
280 15469 2- ⁄2 ⁄4 0.752 1.004
1 7
281 8121 1- ⁄8 ⁄8 0.877 1.004
5 7
282 11730 1- ⁄8 ⁄8 0.877 1.004
283 9281 1- ⁄8 1 1.003 1.129
284 13406 1- ⁄8 1 1.003 1.129
285 15469 1- ⁄8 1 1.003 1.129
286 9281 1- ⁄8 1 1.003 1.254
287 13406 1- ⁄8 1 1.003 1.254
288 15469 1- ⁄8 1 1.003 1.254
289 22681 2- ⁄4 1 1.003 1.254
290 24750 3 1 1.003 1.254
291 6188 ⁄4 1 1.003 1.379
B438−21
TABLE Continued
Static Inner Outer
Dash Length, Nominal
Capacity Diameter, Diameter,
No. L (in.) ID (in.)
(lb) d (in.) D (in.)
292 7219 ⁄8 1 1.003 1.379
293 8250 1 1 1.003 1.379
294 9281 1- ⁄8 1 1.003 1.379
295 10313 1- ⁄4 1 1.003 1.379
296 12375 1- ⁄2 1 1.003 1.379
297 13406 1- ⁄8 1 1.003 1.379
298 14438 1- ⁄4 1 1.003 1.379
299 15469 1- ⁄8 1 1.003 1.379
300 16500 2 1 1.003 1.379
301 18563 2- ⁄4 1 1.003 1.379
302 20625 2- ⁄2 1 1.003 1.379
303 22681 2- ⁄4 1 1.003 1.379
1 1
304 10441 1- ⁄8 1- ⁄8 1.128 1.378
5 1
305 15082 1- ⁄8 1- ⁄8 1.128 1.378
7 1
306 17402 1- ⁄8 1- ⁄8 1.128 1.378
3 1
307 25523 2- ⁄4 1- ⁄8 1.128 1.378
308 27800 3 1- ⁄8 1.128 1.378
1 1
309 11602 1- ⁄8 1- ⁄4 1.2535 1.504
5 1
310 16758 1- ⁄8 1- ⁄4 1.2535 1.504
7 1
311 19336 1- ⁄8 1- ⁄4 1.2535 1.504
312 10313 1 1- ⁄4 1.2535 1.630
1 1
313 11602 1- ⁄8 1- ⁄4 1.2535 1.630
1 1
314 12891 1- ⁄4 1- ⁄4 1.2535 1.630
1 1
315 15469 1- ⁄2 1- ⁄4 1.2535 1.630
5 1
316 16758 1- ⁄8 1- ⁄4 1
...

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: B438 − 17 B438 − 21
Standard Specification for
Bronze-Base Powder Metallurgy (PM) Bearings (Oil-
Impregnated)
This standard is issued under the fixed designation B438; 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 specification covers porous metallic sleeve, flange, thrust, and spherical bronze-base bearings that are produced from
mixed metal powders utilizing powder metallurgy (PM) technology and then impregnated with oil to supply operating lubrication.
1.2 Included are the specifications for the chemical, physical, and mechanical requirements of those bronze-base PM materials that
have been developed and standardized specifically for use in the manufacture of these self-lubricating bearings.
1.3 This specification is applicable to the purchase of bronze-base bearings (oil-impregnated) that were formerly covered by
military specifications and are intended for government or military applications. Those additional government requirements that
only apply to military bearings are listed in the Supplementary Requirements section of this specification.
1.4 This specification accompanies Specification B439 that covers the requirements for Iron-Base Powder Metallurgy (PM)
Bearings, (Oil-Impregnated).
1.5 Typical applications for bronze-base bearings are listed in Appendix X1.
1.6 Bearing dimensional tolerance data are shown in Appendix X2, while engineering information regarding installation and
operating parameters of PM bearings is included in Appendix X3. Additional useful information on self-lubricating bearings can
be found in MPIF Standard 35, ISO 5755 and the technical literature.
1.7 With the exception of density values for which the g/cmthe values for density and the mass used to determine density, for
which the use of the gram per cubic centimetre (g/cm unit ) and gram (g) units is the industry standard, 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.
1.8 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 safety, health, and healthenvironmental practices and determine the applicability of regulatory
limitations prior to use.
This specification is under the jurisdiction of ASTM Committee B09 on Metal Powders and Metal Powder Products and is the direct responsibility of Subcommittee
B09.04 on Bearings.
Current edition approved April 1, 2017April 1, 2021. Published April 2017May 2021. Originally approved in 1966. Last previous edition approved in 20132017 as B438 –
13.17. DOI: 10.1520/B0438-17.10.1520/B0438-21.
Machine Design Magazine, Vol 54, #14, June 17, 1982, pp. 130-142.
*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
B438 − 21
1.9 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.
2. Referenced Documents
2.1 ASTM Standards:
B243 Terminology of Powder Metallurgy
B439 Specification for Iron-Base Powder Metallurgy (PM) Bearings (Oil-Impregnated)
B939 Test Method for Radial Crushing Strength, K, of Powder Metallurgy (PM) Bearings and Structural Materials
B946 Test Method for Surface Finish of Powder Metallurgy (PM) Products
B962 Test Methods for Density of Compacted or Sintered Powder Metallurgy (PM) Products Using Archimedes’ Principle
B963 Test Methods for Oil Content, Oil-Impregnation Efficiency, and Surface-Connected Porosity of Sintered Powder
Metallurgy (PM) Products Using Archimedes’ Principle
E9 Test Methods of Compression Testing of Metallic Materials at Room Temperature
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E1019 Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys by
Various Combustion and Inert Gas Fusion Techniques
2.2 MPIF Standard:
MPIF Standard 35 Materials Standards for PM Self-Lubricating Bearings
2.3 ISO Standard:Standards:
ISO 2795 Plain Bearings Made from Sintered Material—Dimensions and Tolerances
ISO 5755 Sintered Metal Materials - Specifications
2.4 Government Standards:
MIL-PRF-6085 Lubricating Oil: Instrument, Aircraft, Low Volatility
QPL-6085 Lubricating Oil Instrument, Aircraft, Low Volatility
MIL-PRF-17331 Lubrication Oil, Steam Turbine and Gear, Moderate Service
QPL-6085 Lubricating Oil Instrument, Aircraft, Low Volatility
QPL-17331 Lubricating Oil, Steam Turbine and Gear, Moderate Service
3. Terminology
3.1 Definitions—The definitions of the terms used in this specification are found in Terminology B243. Additional descriptive
information is available in the Related Materials section of Volume 02.05 of the under “General Information on PM” on the Annual
Book of ASTM Standards.ASTM B09 web page.
4. Classification
4.1 This specification uses the established three-part alphanumeric PM Material Designation Code to identify the nonferrous
materials used for self-lubricating PM bearings. The complete explanation of this classification system is presented in Annex A1.
4.2 The following standard oil-impregnated bronze-base bearing material compositions are contained in this specification:
4.2.1 Prefix CT—Bronze (Low Graphite):
CT-1000-K19
CT-1000-K26
CT-1000-K37
CT-1000-K40
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.
Available from Metal Powder Industries Federation (MPIF), 105 College Rd. East, Princeton, NJ 08540-6692, http://www.mpif.org.
ISO standards are available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.Available from
International Organization for Standardization (ISO), ISO Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland, https://www.iso.org.
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://dodssp.daps.dla.mil.
Electronic copies of military specifications may be obtained from http://assist.daps.dla.mil/.
B438 − 21
4.2.2 Prefix CTG—Bronze-Graphite (Medium Graphite):
CTG-1001-K17
CTG-1001-K23
CTG-1001-K30
CTG-1001-K34
4.2.3 Prefix CTG—Bronze (High Graphite):
CTG-1004-K10
CTG-1004-K15
4.2.4 Prefix CTG-MOD—Bronze-Lead-Graphite (Military Grade):
CTG-1001-K23-MOD
4.2.5 Prefix CFTG—Bronze (Diluted):
CFTG-3806-K14
CFTG-3806-K22
5. Ordering Information
5.1 Purchase orders or contracts for bronze-base, oil-impregnated bearings covered by this purchasing specification shall include
the following information:
5.1.1 A copy of the bearing print showing dimensions and tolerances (Section 10),
5.1.2 Reference to this ASTM Standard, including date of issue,
5.1.3 Identification of bearing material by the PM Material Designation Code (Section 4.2),
5.1.4 Request for Certification and Test Report documents, if required (Section 16),
5.1.5 Type and grade of special lubricating oil, if required (Section 6.2 or S2.2),
5.1.6 Instructions for special packaging, if required (Section 17).
5.1.7 Chemical composition limits (Sections 7.2 and 13.2) if required,
5.1.8 Sampling lot size (Section 12) if required,
5.1.9 Testing procedure and strength requirement for the flanges of flanged oil-impregnated bearings (Section 13.4.1.2) if required,
5.1.10 Bearing breaking load (Section 13.4.2) if required.
5.2 Those additional government requirements necessary on orders for military bearings are prescribed in the Supplementary
Requirements section.
6. Materials and Manufacture
6.1 Porous Metallic Bearing:
6.1.1 Sintered bronze-base bearings shall be produced by first compacting pre-alloyed bronze or elemental copper and tin powders
and any other additives appropriate for the composition to the proper density and bearing configuration.
B438 − 21
6.1.2 The green bearings shall then be sintered in a protective atmosphere furnace for a time and temperature relationship that will
produce the required sintered bronze-base PM material.
6.1.3 After sintering, the bronze-base bearings are normally sized to achieve the density, dimensional characteristics, concentricity,
and surface finish required of the metallic bearing.
6.2 Oil for Operating Lubrication:
6.2.1 The surface-connected porosity in the bearings shall be filled to the required volume with lubricating oil, either by an
extended soaking in the hot oil or preferably by a vacuum impregnation operation.
6.2.2 A medium viscosity petroleum oil is normally used for most bearing applications, but extreme operating conditions such as
elevated temperatures, intermittent rotation, extremely low speeds, or heavy loads may require a synthetic lubricant or an oil with
a different viscosity.
6.2.3 Unless otherwise specified by the purchaser, a high-grade turbine oil with antifoaming additives and containing corrosion
-6 -6 2
and oxidation inhibitors, having a kinematic viscosity of 280 to 500 SSU [(60 × 10 to 110 × 10 m /s), (60 to 110 cSt)] at 100
°F (38 °C) is normally used as a general purpose lubricating oil.
7. Chemical Composition
7.1 Chemical Composition Specifications—Each bronze-base PM bearing material shall conform to the chemical requirements
prescribed in Table 1 when determined on a clean test sample from oil-free bearings.
TABLE 1 Specifications for Bronze-Base Materials used in PM Bearings
Physical Mechanical
Chemical Requirements
Requirements Requirements
Radial Crushing
Material Designation Code Strength, K
Graphitic All
Copper Tin Lead Iron
Carbon Others
Impregnated Content
mass % mass % mass % mass %
mass % mass %
Density Oil 10 psi (MPa)
g/cm vol %
Bronze (Low Graphite)
A,G
CT-1000-K19 bal 9.5-10.5 — 0.3 max 1.0 max 1.0 max 6.0-6.4 24 min 19 min (130 min)
G
CT-1000-K26 bal 9.5-10.5 — 0.3 max 1.0 max 1.0 max 6.4-6.8 19 min 26 min (180 min)
G
CT-1000-K37 bal 9.5-10.5 — 0.3 max 1.0 max 1.0 max 6.8-7.2 12 min 37 min (260 min)
G
CT-1000-K40 bal 9.5-10.5 — 0.3 max 1.0 max 1.0 max 7.2-7.6 9 min 40 min (280 min)
Bronze (Medium Graphite)
B,G
CTG-1001-K17 bal 9.5-10.5 — 0.5-1.8 1.0 max 1.0 max 6.0-6.4 22 min 17 min (120 min)
G
CTG-1001-K23 bal 9.5-10.5 — 0.5-1.8 1.0 max 1.0 max 6.4-6.8 17 min 23 min (160 min)
G
CTG-1001-K30 bal 9.5-10.5 — 0.5-1.8 1.0 max 1.0 max 6.8.7.2 9 min 30 min (210 min)
G
CTG-1001-K34 bal 9.5-10.5 — 0.5-1.8 1.0 max 1.0 max 7.2-7.6 7 min 34 min (230 min)
Bronze (High Graphite)
G,I
CTG-1004-K10 bal 9.2-10.2 — 2.5-5.0 1.0 max 1.0 max 5.8-6.2 11 min 10 min (70 min)
C,G
CTG-1004-K15 bal 9.2-10.2 — 2.5-5.0 1.0 max 1.0 max 6.2-6.6 15 min (100 min)
Bronze-Lead-Graphite (Military Grade)
D G
CTG-1001-K23-MOD bal 9.5-10.5 2.0-4.0 0.5-1.75 1.0 max 0.5 max 6.4-6.8 17 min 23 min (160 min)
Bronze (Diluted)
E F H
CFTG-3806-K14 bal 5.5-6.5 — 36.0-40.0 2.0 max 5.6-6.0 22 min 14-35 (100-240)
E F H
CFTG-3806-K22 bal 5.5-6.5 — 36.0-40.0 2.0 max 6.0-6.4 17 min 22-50 (150-340)
A 3
For an oil content of 27%27 % min, density range will be 5.8-6.2 g/cm and radial crushing strength will be 15 000 psi (100 MPa) minimum.
B 3
For an oil content of 25%25 % min, density range will be 5.8-6.2 g/cm and radial crushing strength will be 13 000 psi (90 MPa) minimum.
C 3 3
At maximum graphite (5%)(5 %) and density (6.6 g/cm ), this material will contain only a trace of oil. At 3%3 % graphite and 6.2-6.6 g/cm density, it will contain 8 vol
% vol % (min.) of oil.
D
Additional chemical requirements are: Zinc–0.75%Zinc–0.75 % max, Nickel–0.35%Nickel–0.35 % max, Antimony–0.25%Antimony–0.25 % max.
E
Graphitic carbon content is typically 0.5-1.3%;0.5-1.3 %; total carbon shall be 0.5-1.3%.0.5-1.3 %.
F
The iron portion may contain 0.5%0.5 % max metallurgically combined carbon.
G
Minimum oil content will decrease with increasing density. Those shown are valid at the upper-limit of the density given.
H
These data are based on material in the finished condition.
I
At 3%3 % graphite, it will contain 14%14 % min oil content.
B438 − 21
7.2 Limits on Nonspecified Elements—By agreement between the purchaser and the producer, limits may be established and
chemical analyses required for elements or compounds not specified in Table 1.
8. Physical Properties
8.1 Oil Content—For each bearing material, the oil content of the as-received bearing shall not be less than the minimum
percentage listed in Table 1.
8.2 Impregnation Effıciency—A minimum of 90%90 % of the interconnectedsurface-connected porosity in the as-received
bearings shall be impregnated with lubricating oil.
8.3 Impregnated Density—The density of the sample bearings, when fully impregnated with lubricating oil, shall meet the
requirements prescribed in Table 1 for each bearing material.
9. Mechanical Properties
9.1 Radial Crushing Strength—The radial crushing strength of the oil-impregnated bearing material determined on a plain sleeve
bearing or a test specimen prepared from a flange or spherical bearing shall meet the minimum and maximum (if required) strength
values listed in Table 1.
10. Dimensions, Mass, and Permissible Variations
10.1 This standard is applicable to bronze-base PM sleeve and flange bearings having a 4 to 1 maximum length to inside diameter
ratio and a 24 to 1 maximum length to wall thickness ratio.
10.2 Sleeve, flange, thrust, and spherical PM bearings covered by this specification are illustrated by Figs. 1-4. Most PM bearings
are small and weigh less than one-quarter pound (~100 g) but they can be produced in sizes that will accommodate shafts up to
approximately 8 in. (200 mm) in diameter.
10.3 Permissible variations in dimensions shall be within the tolerance limits shown on the bearing print accompanying the order
or shall be within the limits specified in the purchase order or contract. Dimensional tolerances of bearings for military or
government applications shall meet the requirements specified in the Supplementary Requirements section.
10.4 Recommended commercial tolerances for bronze-base PM bearings are referenced throughout the tables in Appendix X2.
10.5 Chamfers of 30-45° are generally used on PM bearings to break the corners.
11. Workmanship, Finish, and Appearance
11.1 The bearings should have a matte surface and not show oxidation. The surfaces of sized bearings should have a smooth, bright
finish.
11.2 When cut or fractured, the exposed surface of the bearings should exhibit a uniform visual appearance.
FIG. 1 Standard Sleeve Bearing
B438 − 21
FIG. 2 Standard Flange Bearing
FIG. 3 Standard Thrust Bearing
FIG. 4 Standard Spherical Bearing
11.3 If metallographic examination is performed to determine degree of sintering, it should be done at 200-400X magnification.
In 90Cu-10Sn bronze bearings, the microstructure should be alpha bronze with no silver-gray tin-rich copper compounds and with
a minimum of reddish copper-rich areas. The structure should have a very minimum number of original particle boundaries.
Diluted bronze material should show a bronze phase with no visible free tin, dispersed throughout an iron matrix.
11.4 To verify that oil is present, heat the bearing to about 300 °F (150 °C) for 5 minutes. 5 min. If oil is present, the bearing
surfaces exhibit beads of oil being exuded from the pores.
11.5 When bearings are ordered as being “dry-to-the-touch” to allow automated handling by the purchaser, the excess surface oil
is normally removed by a centrifugal operation. It is important that the Oil Content test (13.3.2) be performed after the surface
drying treatment to make certain that the required volume of lubricating oil is present.
12. Sampling
12.1 Lot—Unless otherwise specified, a lot shall be defined as a specific quantity of bearings manufactured under traceable,
controlled conditions as agreed to between the producer and purchaser (Terminology B243).
12.2 Sampling Plan—The number of sample bearings, agreed to between the producer and the purchaser, to be used for
inspections shall be taken randomly from locations throughout the lot.
13. Test Methods
13.1 Dimensional Measurements:
B438 − 21
13.1.1 Using suitable measuring equipment, the inside diameter of the bearings shall be measured to the nearest 0.0001 in. (0.0025
mm). The other bearing dimensions only require instrumentation capable of measuring to the tolerances specified on the bearing
drawing.
13.2 Chemical Analysis:
13.2.1 Oil Extraction—Bearings must be dry and free of oil before running chemical tests. To remove oil, a Soxhlet Apparatus
as specified in Test Method B963 may be used. However, upon agreement between purchaser and producer, a low-temperature
furnace treatment [1000 to 1200 °F (540 to 650 °C)] with a flowing nitrogen or inert atmosphere may be used to volatilize any
lubricant that may be present.
13.2.2 Metallic Elements—The chemical analysis of metallic elements shall be performed on an oil-free sample in accordance with
the test methods prescribed in Volume 03.05 of the Annual Book of ASTM Standards or by another approved method agreed upon
between the producer and the purchaser.
13.2.3 Combined Carbon—To determine the amount of carbon metallurgically combined with the iron in the diluted bronze
materials, a metallographic estimate may be made.
13.2.4 Graphitic Carbon—Determine the total carbon content in accordance with Test Method E1019 with the exception that a
sample as small as 0.25 g may be used upon agreement between purchaser and producer. With the exception of diluted bronze,
the graphitic carbon provides an estimate of the total carbon. For diluted bronze, the graphitic carbon is approximately equal to
the total carbon minus the combined carbon as determined in 13.2.3.
13.3 Physical Properties:
13.3.1 Oil Content—The oil content of the as-received bearing shall be determined following the procedure for As-Received Oil
Content in Test Method B963.
13.3.2 Impregnation Effıciency—The efficiency of the oil-impregnation process in volume percent units shall be calculated
following the procedure for Oil-Impregnation Effıciency in Test Method B963.
13.3.3 Impregnated Density—The impregnated density of the sample bearings in g/cm units, measured after they have been fully
impregnated, shall be determined following the procedure for Determination of Impregnated Density in Test Method B962.
13.4 Mechanical Properties:
13.4.1 Radial Crushing Strength—Radial crushing strength in psi (MPa) is the mechanical property by which the strength of
oil-impregnated PM bearing material is characterized and evaluated. It is determined by breaking plain thin-walled bearings or
hollow cylindrical test specimens under diametrical loading, following the procedures described in Test Method B939, and
calculating the radial crushing strength according to the material strength formula contained therein.
13.4.1.1 Plain sleeve bearings and thrust bearings are tested in the oil-impregnated condition. For acceptance, the radial crushing
strength, determined on the test bearings, shall not be less than the minimum nor more than the maximum (if applicable) strength
specification values listed in Table 1 for the bearing material.
13.4.1.2 Flanged oil-impregnated bearings shall be tested by cutting off the flange and crushing the body as a plain sleeve bearing.
For acceptance, the radial crushing strength so determined shall meet the minimum and maximum (if applicable) material strength
requirements prescribed in Table 1. The testing procedure and material strength requirements of the flange shall be a matter of
agreement between producer and purchaser.
13.4.1.3 To evaluate spherical, or bearings of other configuration, a number of sample bearings from the lot shall first be machined
to a right circular cylinder, measured, and then crushed to determine the radial crushing strength of the oil-impregnated bearing
material. This value shall not be less than the minimum nor more than the maximum (if applicable) radial crushing strength
specified in Table 1 for the material in the sample bearings.
13.4.2 Bearing Breaking Load—If agreed to by the producer and the purchaser, an acceptance specification for the minimum
B438 − 21
(maximum) bearing breaking load, P (P ) in lbf (N), may be established for any specific standard oil-impregnated bearing.
min, max
This simplifies acceptance testing because the decision is now based solely upon reading the output of the testing machine without
a need for further calculations. This acceptance procedure can be very useful when evaluating multiple or repeat shipments of the
same bearing.
13.4.2.1 The minimum (maximum) breaking load, P (P ) required for acceptance of any specific plain sleeve or thrust
min, max
bearing is calculated using the breaking load formula:
K 3L 3t
P P 5 (1)
~ !
min, max
D 2 t
where:
P (P = minimum (maximum) bearing breaking load, lbf (N),
min, max)
K = minimum (maximum) radial crushing strength, psi (MPa),
L = length of bearing, in. (mm),
t = wall thickness, [t = (D – d) / 2], in. (mm),
D = outside diameter, in. (mm), and
d = inside diameter, in. (mm).
13.4.2.2 Use the minimum (maximum) radial crushing strength value specified for the oil-impregnated bearing material from
Table 1 for K, use the actual D,d and L dimensions of the as-received bearing and solve for P (P ). This calculated value will
min, max
be the minimum (maximum) acceptable breaking load for that specific plain bearing. Using the allowable print dimensions that
minimize (maximize) the volume of the bearing for the calculations will result in a breaking load specification(s) that will be
applicable to any lot of that specific bearing.
13.4.2.3 The minimum (maximum) acceptable breaking load for a specific flanged bearing shall be calculated by first cutting off
the flange and measuring the D,d, and L of the body. Then, using the minimum (maximum) radial crushing strength for the
oil-impregnated bearing material in Table 1 for K in the breaking load formula and the measured dimensions of the body, a
P (P ) value may be calculated. This will be the minimum (maximum) bearing breaking load required for the body of that
min, max
specific flanged bearing. The test procedure and breaking load requirements for the flange shall be a matter of agreement between
purchaser and producer.
13.4.2.4 For acceptance testing of whole spherical bearings, a minimum (maximum) bearing breaking load specification,
P (P ) may be established on a specific whole spherical oil-impregnated bearing. First, the radial crushing strength, K , is
min, max a
determined on that specific spherical bearing machined to a plain cylinder as in 13.4.1.3. Second, whole spherical bearings from
the same lot are crushed, keeping their axes horizontal, to determine the breaking load of the whole bearing. Then, using the
correlation formula, the specifications for the breaking load, P of that whole spherical bearing are calculated as follows:
a,
K 3P
a
P P 5 (2)
~ !
min, max
K
a
where:
P (P ) = specification for the minimum (maximum) bearing breaking load of a specific whole spherical bearing, lbf (N),
min, max
K = radial crushing strength of the machined test spherical bearings according to 13.4.1.3, psi (MPa),
a
K = minimum (maximum) radial crushing strength for the bearing material, (Table 1), psi (MPa), and
P = breaking load of whole test spherical bearings, lbf (N).
a
13.5 Conformance:
13.5.1 Dimensional Measurements—For purposes of determining conformance with the dimensional specifications, the tolerance
limits specified on the bearing print are considered absolute limits as defined in Practice E29.
13.5.2 Chemical, Physical, Mechanical Test Results—For purposes of determining conformance with these specifications, an
observed value or calculated value shall be rounded “to the nearest unit” in the last right-hand digit used in expressing the
specification limit, in accordance with the rounding-off method of Practice E29.
13.5.3 Measurement Uncertainty—The precision and bias of the test result values shall be considered by the purchaser and
producer in determining conformance.
B438 − 21
14. Inspection
14.1 The producer has the primary responsibility to conduct the necessary measurements and tests to ensure that the bearings meet
the requirements of the purchase order or contract and this specification before they are shipped to the purchaser.
14.2 Provided the producer notifies the purchaser, all or a portion of the required conformance tests may be contracted to a
qualified third party.
14.3 Upon receipt of the shipment, the purchaser may conduct whatever quality control inspections that he feels are necessary to
confirm compliance to the purchasing requirements.
15. Rejection and Rehearing
15.1 Rejection based on tests made in accordance with this specification shall be reported in writing to the producer within 30 days
of receipt of the shipment; the rejected bearings, however, shall not be returned or disposed of without written authorization from
the producer.
15.2 In case of dissatisfaction with the test results, either the purchaser or producer may make a claim for rehearing.
16. Certification and Test Report
16.1 The purchaser may require in the purchase order or contract that the producer shall supply a Certificate of Compliance stating
that the bearings were produced and tested in accordance with this specification and met all requirements.
16.2 In addition, when required by the purchase order or contract, the producer shall furnish a Test Report that lists the results of
the chemical, physical, mechanical, and functional tests performed on the sample bearings.
16.3 Unless otherwise agreed upon between the purchaser and the producer, the Certificate of Compliance, the Test Report, or both
will be transmitted by electronic service.
17. Packaging
17.1 Unless specific packaging requirements are included in the purchase order or contract, the finished oil-impregnated PM
bearings shall be packaged and shipped in containers of a nonabsorbent material to prevent loss of lubricating oil.
18. Keywords
18.1 bearing breaking load; bronze bearings; impregnated density; interconnected porosity; oil content; oil-impregnated bearings;
open porosity; PM bearings; porous metallic bearings; PV Factor; PV Limit; radial crushing strength; self-lubricating bearings;
bearingsPM bearings; PV Factor; PV Limit
SUPPLEMENTARY REQUIREMENTS
MILITARY BEARINGS, SINTERED BRONZE, OIL-IMPREGNATED
The following supplementary requirements shall apply to purchase orders or contracts from all
agencies of the United States Government or where specified by a purchaser as part of the purchase
order or contract with a government agency.
B438 − 21
S1. Introduction
S1.1 The B438 purchasing specification incorporates and updates the applicable portions of specifications from four
now-cancelled military standards, bringing the military requirements into alignment with the rest of this consensus specification.
The type and grade designations from four now-cancelled military standards have been converted to the industry accepted material
designation codes from MPIF Standard 35 (Bearings) (see Table A2.1 for conversion information). In addition to meeting the
primary specifications, the purchaser of bearings for military or government applications must comply with additional specific
requirements. This Supplementary Requirements section details those additional governmental requirements.
S1.2 The bearings referred to within this specification are not intended for reaming on assembly.
S1.3 The bearings referred to within this specification are not recommended for military airframe applications.
S2. Government Requirements
S2.1 Chemical, Physical and Mechanical Requirements—Refer to Section 1 and Table 1 for the specifications for bearing
materials that shall conform to material designation codes CTG-1001-K23 (sleeve, flange and thrust washer) or CTG-1001-K23-
MOD (sleeve and flange only). The contractor shall furnish a chemical composition analysis on an oil-free basis for each lot
showing the weight percentage for each element as specified in Table 1. Bearings shall conform to this specification.
S2.1.1 Compressive Yield Strength—The yield strength in compression shall be 11 000 psi (75 MPa) (minimum) for 0.1 percent
permanent offset in accordance with section X3.2.1.
S2.1.2 Surface Finish—For thrust washer bearings, all surfaces shall have a surface finish of 125 μin. maximum, except as noted
on a print or drawing. Surface finish shall be measured in accordance with Test Method B946.
S2.2 Oil-Impregnation—High-grade non-gumming petroleum lubricants purchased in accordance with the applicable Qualified
Products Lists (QPLs), such as MIL-PRF-17331 (Military Symbol 2190–TEP, NATO Code O-250 and QPL-17331) for sleeve and
flange bearings and MIL-PRF-6085 (Military Symbol OAI, NATO Code No. 0-147 and QPL-6085) for thrust washer bearings, or
as specified on referenced military standard specification sheets shall be used to impregnate the bearings.
S2.3 First Article Tests (FAT)—When specified in the contract, FATs shall be performed on a number of samples (four
minimum). The tests performed shall conform to 12.2, Sampling Plan and shall include testing for interconnected porosity. Testing
shall be as specified within this specification, Test Method B963 or in another document as specified in the contract. Any defect
or failure shall be cause for rejection of the lot. Waivers for minor defects may be addressed to the contracting officer.
Note—InNote—In order to perform all the tests on a single bearing, the following order of tests is suggested: dimensional,
impregnated density, interconnected porosity, oil content, oil exudation, radial crushing strength and chemical analysis.
S2.4 Oil Exudation Test—During the test period for oil exudation, beads shall exude from the bearing surface. Lack of
appreciable sweating of the lubricant on the bearing surface will be cause for rejection (see 11.4).
S2.5 COQC—When procured from a dealer or distributor versus the actual producer, a certificate of quality conformance
(COQC) supplied by the producer of the bearing may be furnished in lieu of actual performance of such testing by the dealer or
distributor, provided lot identity is traceable, has been maintained and can be demonstrated to the Government. The certificate shall
include the name of the dealer or distributor, dealer or distributor number, name of producer, national stock number (NSN), item
identification, name of the component or material, lot number, lot size, dimensions, date of testing, test method, individual test
results, and specification requirements.
S2.6 Records—Records of examination and tests performed by or for the contractor shall be maintained and made available to
the Government by the contractor for a period of three years after delivery of the products and associate material.
S2.7 Inspection—Unless otherwise specified, the producer is responsible for testing. The producer may use their own or any
other suitable facility for the performance of testing and inspection, unless an exception is stated. The Government reserves the
right to perform an inspection as set forth herein to assure supplies and sources conform to the prescribed requirements.
S2.8 Packaging—Special packaging and marking requirements shall be included in the contract or will conform to Section 17,
Packaging.
S2.9 Requirements—All requirements shall be as specified herein. Referenced military standard specification sheets shall take
precedence unless otherwise specified in the purchase order or contract.
S3. Ordering Information
S3.1 Purchase Order or Contract—Ordering information shall be in accordance with Section 5 of this specification and shall
also include:
S3.1.1 PIN from S3.3, Table S3.1, Table S3.2 or Table S3.3,
B438 − 21
TABLE S3.1 MS17795 Bronze Sleeve Bearings—Dimensions and
Dash Numbers
Static Inner Outer
Dash Length, Nominal
Capacity Diameter, Diameter,
No. L (in.) ID (in.)
(lb) d (in.) D (in.)
3 1
1 97 ⁄32 ⁄8 0.127 0.1905
1 1
2 129 ⁄8 ⁄8 0.127 0.1905
3 1
3 194 ⁄16 ⁄8 0.127 0.1905
1 1
4 258 ⁄4 ⁄8 0.127 0.1905
1 1
5 129 ⁄8 ⁄8 0.127 0.253
3 1
6 194 ⁄16 ⁄8 0.127 0.253
1 1
7 258 ⁄4 ⁄8 0.127 0.253
5 1
8 323 ⁄16 ⁄8 0.127 0.253
1 3
9 193 ⁄8 ⁄16 0.1895 0.253
3 3
10 290 ⁄16 ⁄16 0.1895 0.253
1 3
11 387 ⁄4 ⁄16 0.1895 0.253
5 3
12 483 ⁄16 ⁄16 0.1895 0.253
3 3
13 580 ⁄8 ⁄16 0.1895 0.253
7 3
14 677 ⁄16 ⁄16 0.1895 0.253
3 3
15 290 ⁄16 ⁄16 0.1895 0.3155
1 3
16 387 ⁄4 ⁄16 0.1895 0.3155
5 3
17 483 ⁄16 ⁄16 0.1895 0.3155
3 3
18 580 ⁄8 ⁄16 0.1895 0.3155
7 3
19 677 ⁄16 ⁄16 0.1895 0.3155
1 3
20 774 ⁄2 ⁄16 0.1895 0.3155
3 1
21 386 ⁄16 ⁄4 0.252 0.378
1 1
22 516 ⁄4 ⁄4 0.252 0.378
5 1
23 645 ⁄16 ⁄4 0.252 0.378
3 1
24 773 ⁄8 ⁄4 0.252 0.378
7 1
25 902 ⁄16 ⁄4 0.252 0.378
1 1
26 1031 ⁄2 ⁄4 0.252 0.378
5 1
27 1289 ⁄8 ⁄4 0.252 0.378
3 1
28 386 ⁄16 ⁄4 0.252 0.4405
1 1
29 516 ⁄4 ⁄4 0.252 0.4405
5 1
30 645 ⁄16 ⁄4 0.252 0.4405
3 1
31 773 ⁄8 ⁄4 0.252 0.4405
7 1
32 902 ⁄16 ⁄4 0.252 0.4405
1 1
33 1031 ⁄2 ⁄4 0.252 0.4405
5 1
34 1289 ⁄8 ⁄4 0.252 0.4405
3 1
35 1547 ⁄4 ⁄4 0.252 0.4405
1 5
36 645 ⁄4 ⁄16 0.3145 0.4405
5 5
37 806 ⁄16 ⁄16 0.3145 0.4405
3 5
38 967 ⁄8 ⁄16 0.3145 0.4405
7 5
39 1128 ⁄16 ⁄16 0.3145 0.4405
1 5
40 1289 ⁄2 ⁄16 0.3145 0.4405
5 5
41 1611 ⁄8 ⁄16 0.3145 0.4405
3 5
42 1934 ⁄4 ⁄16 0.3145 0.4405
1 3
43 773 ⁄4 ⁄8 0.377 0.503
5 3
44 967 ⁄16 ⁄8 0.377 0.503
3 3
45 1160 ⁄8 ⁄8 0.377 0.503
7 3
46 1354 ⁄16 ⁄8 0.377 0.503
1 3
47 1547 ⁄2 ⁄8 0.377 0.503
5 3
48 1934 ⁄8 ⁄8 0.377 0.503
3 3
49 2320 ⁄4 ⁄8 0.377 0.503
7 3
50 2707 ⁄8 ⁄8 0.377 0.503
51 3094 1 ⁄8 0.377 0.503
1 3
52 773 ⁄4 ⁄8 0.377 0.628
5 3
53 967 ⁄16 ⁄8 0.377 0.628
3 3
54 1160 ⁄8 ⁄8 0.377 0.628
7 3
55 1354 ⁄16 ⁄8 0.377 0.628
1 3
56 1547 ⁄2 ⁄8 0.377 0.628
5 3
57 1934 ⁄8 ⁄8 0.377 0.628
3 3
58 2320 ⁄4 ⁄8 0.377 0.628
7 3
59 2707 ⁄8 ⁄8 0.377 0.628
60 3094 1 ⁄8 0.377 0.628
1 3
61 3867 1- ⁄4 ⁄8 0.377 0.628
3 7
62 1354 ⁄8 ⁄16 0.439 0.565
7 7
63 1579 ⁄16 ⁄16 0.439 0.565
1 7
64 1805 ⁄2 ⁄16 0.439 0.565
5 7
65 2256 ⁄8 ⁄16 0.439 0.565
3 7
66 2707 ⁄4 ⁄16 0.439 0.565
7 7
67 3158 ⁄8 ⁄16 0.439 0.565
68 3609 1 ⁄16 0.439 0.565
1 7
69 4512 1- ⁄4 ⁄16 0.439 0.565
3 1
70 1547 ⁄8 ⁄2 0.502 0.628
7 1
71 1805 ⁄16 ⁄2 0.502 0.628
1 1
72 2063 ⁄2 ⁄2 0.502 0.628
B438 − 21
TABLE Continued
Static Inner Outer
Dash Length, Nominal
Capacity Diameter, Diameter,
No. L (in.) ID (in.)
(lb) d (in.) D (in.)
5 1
73 2578 ⁄8 ⁄2 0.502 0.628
3 1
74 3094 ⁄4 ⁄2 0.502 0.628
7 1
75 3609 ⁄8 ⁄2 0.502 0.628
76 4125 1 ⁄2 0.502 0.628
1 1
77 5156 1- ⁄4 ⁄2 0.502 0.628
3 1
78 1547 ⁄8 ⁄2 0.502 0.753
1 1
79 2063 ⁄2 ⁄2 0.502 0.753
5 1
80 2578 ⁄8 ⁄2 0.502 0.753
3 1
81 3094 ⁄4 ⁄2 0.502 0.753
7 1
82 3609 ⁄8 ⁄2 0.502 0.753
83 4125 1 ⁄2 0.502 0.753
1 1
84 5156 1- ⁄4 ⁄2 0.502 0.753
1 1
85 6188 1- ⁄2 ⁄2 0.502 0.753
1 9
86 2320 ⁄2 ⁄16 0.565 0.695
5 9
87 2900 ⁄8 ⁄16 0.565 0.695
3 9
88 3480 ⁄4 ⁄16 0.565 0.695
7 9
89 4061 ⁄8 ⁄16 0.565 0.695
90 4641 1 ⁄16 0.565 0.695
1 9
91 5801 1- ⁄4 ⁄16 0.565 0.695
1 9
92 6961 1- ⁄2 ⁄16 0.565 0.695
1 5
93 2578 ⁄2 ⁄8 0.627 0.753
5 5
94 3223 ⁄8 ⁄8 0.627 0.753
3 5
95 3867 ⁄4 ⁄8 0.627 0.753
7 5
96 4518 ⁄8 ⁄8 0.627 0.753
97 5156 1 ⁄8 0.627 0.753
1 5
98 6445 1- ⁄4 ⁄8 0.627 0.753
1 5
99 7734 1- ⁄2 ⁄8 0.627 0.753
1 5
100 2578 ⁄2 ⁄8 0.627 0.879
5 5
101 3223 ⁄8 ⁄8 0.627 0.879
3 5
102 3867 ⁄4 ⁄8 0.627 0.879
7 5
103 4518 ⁄8 ⁄8 0.627 0.879
104 5156 1 ⁄8 0.627 0.879
1 5
105 6445 1- ⁄4 ⁄8 0.627 0.879
1 5
106 7734 1- ⁄2 ⁄8 0.627 0.879
3 5
107 9023 1- ⁄4 ⁄8 0.627 0.879
1 3
108 3094 ⁄2 ⁄4 0.752 0.879
5 3
109 3867 ⁄8 ⁄4 0.752 0.879
3 3
110 4640 ⁄4 ⁄4 0.752 0.879
7 3
111 5414 ⁄8 ⁄4 0.752 0.879
112 6188 1 ⁄4 0.752 0.879
1 3
113 7734 1- ⁄4 ⁄4 0.752 0.879
1 3
114 9281 1- ⁄2 ⁄4 0.752 0.879
3 3
115 10828 1- ⁄4 ⁄4 0.752 0.879
1 3
116 3094 ⁄2 ⁄4 0.752 1.004
5 3
117 3867 ⁄8 ⁄4 0.752 1.004
3 3
118 4640 ⁄4 ⁄4 0.752 1.004
7 3
119 5414 ⁄8 ⁄4 0.752 1.004
120 6188 1 ⁄4 0.752 1.004
1 3
121 7734 1- ⁄4 ⁄4 0.752 1.004
1 3
122 9281 1- ⁄2 ⁄4 0.752 1.004
3 3
123 10828 1- ⁄4 ⁄4 0.752 1.004
124 12375 2 ⁄4 0.752 1.004
5 7
125 4512 ⁄8 ⁄8 0.877 1.004
3 7
126 5414 ⁄4 ⁄8 0.877 1.004
7 7
127 6316 ⁄8 ⁄8 0.877 1.004
128 7219 1 ⁄8 0.877 1.004
1 7
129 9023 1- ⁄4 ⁄8 0.877 1.004
1 7
130 10828 1- ⁄2 ⁄8 0.877 1.004
3 7
131 12633 1- ⁄4 ⁄8 0.877 1.004
132 6188 ⁄4 1 1.003 1.129
133 7219 ⁄8 1 1.003 1.129
134 8250 1 1 1.003 1.129
135 10313 1- ⁄4 1 1.003 1.129
136 12375 1- ⁄2 1 1.003 1.129
137 14438 1- ⁄4 1 1.003 1.129
138 16500 2 1 1.003 1.129
139 6188 ⁄4 1 1.003 1.254
140 7219 ⁄8 1 1.003 1.254
141 8250 1 1 1.003 1.254
142 10313 1- ⁄4 1 1.003 1.254
143 12375 1- ⁄2 1 1.003 1.254
144 14438 1- ⁄4 1 1.003 1.254
145 16500 2 1 1.003 1.254
B438 − 21
TABLE Continued
Static Inner Outer
Dash Length, Nominal
Capacity Diameter, Diameter,
No. L (in.) ID (in.)
(lb) d (in.) D (in.)
146 18563 2- ⁄4 1 1.003 1.254
147 20625 2- ⁄2 1 1.003 1.254
148 9281 1 1- ⁄8 1.128 1.378
1 1
149 11602 1- ⁄4 1- ⁄8 1.128 1.378
1 1
150 13922 1- ⁄2 1- ⁄8 1.128 1.378
3 1
151 16242 1- ⁄4 1- ⁄8 1.128 1.378
152 18563 2 1- ⁄8 1.128 1.378
1 1
153 20883 2- ⁄4 1- ⁄8 1.128 1.378
1 1
154 23203 2- ⁄2 1- ⁄8 1.128 1.378
155 10313 1 1- ⁄4 1.2535 1.504
1 1
156 12891 1- ⁄4 1- ⁄4 1.2535 1.504
1 1
157 15469 1- ⁄2 1- ⁄4 1.2535 1.504
3 1
158 18047 1- ⁄4 1- ⁄4 1.2535 1.504
159 20625 2 1- ⁄4 1.2535 1.504
1 1
160 23203 2- ⁄4 1- ⁄4 1.2535 1.504
1 1
161 25781 2- ⁄2 1- ⁄4 1.2535 1.504
3 1
162 28359 2- ⁄4 1- ⁄4 1.2535 1.504
163 30938 3 1- ⁄4 1.2535 1.504
164 11344 1 1- ⁄8 1.378 1.629
1 3
165 14180 1- ⁄4 1- ⁄8 1.378 1.629
1 3
166 17016 1- ⁄2 1- ⁄8 1.378 1.629
3 3
167 19852 1- ⁄4 1- ⁄8 1.378 1.629
168 22688 2 1- ⁄8 1.378 1.629
1 3
169 25523 2- ⁄4 1- ⁄8 1.378 1.629
1 3
170 28359 2- ⁄2 1- ⁄8 1.378 1.629
3 3
171 31195 2- ⁄4 1- ⁄8 1.378 1.629
172 34031 3 1- ⁄8 1.378 1.629
173 12375 1 1- ⁄2 1.504 1.755
1 1
174 15469 1- ⁄4 1- ⁄2 1.504 1.755
1 1
175 18563 1- ⁄2 1- ⁄2 1.504 1.755
3 1
176 21656 1- ⁄4 1- ⁄2 1.504 1.755
177 24750 2 1- ⁄2 1.504 1.755
1 1
178 27844 2- ⁄4 1- ⁄2 1.504 1.755
1 1
179 30938 2- ⁄2 1- ⁄2 1.504 1.755
3 1
180 34031 2- ⁄4 1- ⁄2 1.504 1.755
181 37125 3 1- ⁄2 1.504 1.755
1 3
182 21656 1- ⁄2 1- ⁄4 1.753 2.005
3 3
183 25266 1- ⁄4 1- ⁄4 1.753 2.005
184 28875 2 1- ⁄4 1.753 2.005
1 3
185 32484 2- ⁄4 1- ⁄4 1.753 2.005
1 3
186 36094 2- ⁄2 1- ⁄4 1.753 2.005
3 3
187 39703 2- ⁄4 1- ⁄4 1.753 2.005
188 43313 3 1- ⁄4 1.753 2.005
189 28875 1- ⁄4 2 2.004 2.38
190 33000 2 2 2.004 2.38
191 37125 2- ⁄4 2 2.004 2.38
192 41250 2- ⁄2 2 2.004 2.38
193 45375 2- ⁄4 2 2.004 2.38
194 49500 3 2 2.004 2.38
195 57750 3- ⁄2 2 2.004 2.38
196 66000 4 2 2.004 2.38
197 37125 2 2- ⁄4 2.254 2.631
1 1
198 46406 2- ⁄2 2- ⁄4 2.254 2.631
199 55688 3 2- ⁄4 2.254 2.631
1 1
200 64969 3- ⁄2 2- ⁄4 2.254 2.631
201 74250 4 2- ⁄4 2.254 2.631
202 41250 2 2- ⁄2 2.505 3.006
1 1
203 51563 2- ⁄2 2- ⁄2 2.505 3.006
204 61875 3 2- ⁄2 2.505 3.006
1 1
205 72188 3- ⁄2 2- ⁄2 2.505 3.006
206 82500 4 2- ⁄2 2.505 3.006
5 1
207 323 ⁄16 ⁄8 0.127 0.1905
3 1
208 387 ⁄8 ⁄8 0.127 0.1905
7 1
209 451 ⁄16 ⁄8 0.127 0.1905
1 1
210 516 ⁄2 ⁄8 0.127 0.1905
3 1
211 387 ⁄8 ⁄8 0.127 0.253
7 1
212 451 ⁄16 ⁄8 0.127 0.253
1 1
213 516 ⁄2 ⁄8 0.127 0.253
1 5
214 161 ⁄8 ⁄32 0.158 0.253
3 5
215 242 ⁄16 ⁄32 0.158 0.253
1 5
216 322 ⁄4 ⁄32 0.158 0.253
5 5
217 403 ⁄16 ⁄32 0.158 0.253
3 5
218 483 ⁄8 ⁄32 0.158 0.253
B438 − 21
TABLE Continued
Static Inner Outer
Dash Length, Nominal
Capacity Diameter, Diameter,
No. L (in.) ID (in.)
(lb) d (in.) D (in.)
7 5
219 564 ⁄16 ⁄32 0.158 0.253
1 5
220 645 ⁄2 ⁄32 0.158 0.253
1 3
221 774 ⁄2 ⁄16 0.1895 0.253
5 3
222 967 ⁄8 ⁄16 0.1895 0.253
3 3
223 1160 ⁄4 ⁄16 0.1895 0.253
5 3
224 967 ⁄8 ⁄16 0.1895 0.3155
3 3
225 1160 ⁄4 ⁄16 0.1895 0.3155
7 3
226 1354 ⁄8 ⁄16 0.1895 0.3155
227 1546 1 ⁄16 0.1895 0.3155
3 1
228 1547 ⁄4 ⁄4 0.252 0.378
7 1
229 1805 ⁄8 ⁄4 0.252 0.378
230 2063 1 ⁄4 0.252 0.378
1 1
231 2320 1- ⁄8 ⁄4 0.252 0.378
1 1
232 2578 1- ⁄4 ⁄4 0.252 0.378
7 1
233 1805 ⁄8 ⁄4 0.252 0.4405
234 2063 1 ⁄4 0.252 0.4405
1 1
235 2320 1- ⁄8 ⁄4 0.252 0.4405
1 1
236 2578 1- ⁄4 ⁄4 0.252 0.4405
1 1
237 3094 1- ⁄2 ⁄4 0.252 0.4405
7 5
238 2256 ⁄8 ⁄16 0.3145 0.4405
239 2578 1 ⁄16 0.3145 0.4405
1 5
240 2900 1- ⁄8 ⁄16 0.3145 0.4405
1 5
241 3223 1- ⁄4 ⁄16 0.3145 0.4405
1 5
242 3867 1- ⁄2 ⁄16 0.3145 0.4405
1 5
243 645 ⁄4 ⁄16 0.3145 0.503
5 5
244 806 ⁄16 ⁄16 0.3145 0.503
3 5
245 967 ⁄8 ⁄16 0.3145 0.503
7 5
246 1128 ⁄16 ⁄16 0.3145 0.503
1 5
247 1289 ⁄2 ⁄16 0.3145 0.503
5 5
248 1611 ⁄8 ⁄16 0.3145 0.503
3 5
249 1934 ⁄4 ⁄16 0.3145 0.503
7 5
250 2256 ⁄8 ⁄16 0.3145 0.503
251 2578 1 ⁄16 0.3145 0.503
1 5
252 2900 1- ⁄8 ⁄16 0.3145 0.503
1 5
253 3223 1- ⁄4 ⁄16 0.3145 0.503
1 5
254 3867 1- ⁄2 ⁄16 0.3145 0.503
1 3
255 3480 1- ⁄8 ⁄8 0.377 0.503
1 3
256 3867 1- ⁄4 ⁄8 0.377 0.503
1 3
257 4641 1- ⁄2 ⁄8 0.377 0.503
1 3
258 3480 1- ⁄8 ⁄8 0.377 0.628
1 7
259 4061 1- ⁄8 ⁄16 0.439 0.565
1 7
260 5414 1- ⁄2 ⁄16 0.439 0.565
1 1
261 4641 1- ⁄8 ⁄2 0.502 0.628
1 1
262 6188 1- ⁄2 ⁄2 0.502 0.628
5 1
263 6703 1- ⁄8 ⁄2 0.502 0.628
1 1
264 4641 1- ⁄8 ⁄2 0.502 0.753
5 1
265 6703 1- ⁄8 ⁄2 0.502 0.753
3 1
266 7219 1- ⁄4 ⁄2 0.502 0.753
7 1
267 8250 1- ⁄8 ⁄2 0.502 0.753
1 9
268 5221 1- ⁄8 ⁄16 0.565 0.695
1 5
269 5801 1- ⁄8 ⁄8 0.627 0.753
1 5
270 5801 1- ⁄8 ⁄8 0.627 0.879
5 5
271 8379 1- ⁄8 ⁄8 0.627 0.879
7 5
272 9668 1- ⁄8 ⁄8 0.627 0.879
273 10313 2 ⁄8 0.627 0.879
1 3
274 6961 1- ⁄8 ⁄4 0.752 0.879
5 3
275 10055 1- ⁄8 ⁄4 0.752 0.879
1 3
276 6961 1- ⁄8 ⁄4 0.752 1.004
5 3
277 10055 1- ⁄8 ⁄4 0.752 1.004
7 3
278 11602 1- ⁄8 ⁄4 0.752 1.004
1 3
279 13922 2- ⁄4 ⁄4 0.752 1.004
1 3
280 15469 2- ⁄2 ⁄4 0.752 1.004
1 7
281 8121 1- ⁄8 ⁄8 0.877 1.004
5 7
282 11730 1- ⁄8 ⁄8 0.877 1.004
283 9281 1- ⁄8 1 1.003 1.129
284 13406 1- ⁄8 1 1.003 1.129
285 15469 1- ⁄8 1 1.003 1.129
286 9281 1- ⁄8 1 1.003 1.254
287 13406 1- ⁄8 1 1.003 1.254
288 15469 1- ⁄8 1 1.003 1.254
289 22681 2- ⁄4 1 1.003 1.254
290 24750 3 1 1.003 1.254
291 6188 ⁄4 1 1.003 1.379
B438 − 21
TABLE Continued
Static Inner Outer
Dash Length, Nominal
Capacity Diameter, Diameter,
No. L (in.) ID (in.)
(lb) d (in.) D (in.)
292 7219 ⁄8 1 1.003 1.379
293 8250 1 1 1.003 1.379
294 9281 1- ⁄8 1 1.003 1.379
295 10313 1- ⁄4 1 1.003 1.379
296 12375 1- ⁄2 1 1.003 1.379
297 13406 1- ⁄8 1 1.003 1.379
298 14438 1- ⁄4 1 1.003 1.379
299 15469 1- ⁄8 1 1.003 1.379
300 16500 2 1 1.003 1.379
301 18563 2- ⁄4 1 1.003 1.379
302 20625 2- ⁄2 1 1.003 1.379
303 22681 2- ⁄4 1 1.003 1.379
1 1
304 10441 1- ⁄8 1- ⁄8 1.128 1.378
5 1
305 15082 1- ⁄8 1- ⁄8 1.128 1.378
7 1
306 17402 1- ⁄8 1- ⁄8 1.128 1.378
3 1
307 25523 2- ⁄4 1- ⁄8 1.128 1.378
308 27800 3 1- ⁄8 1.128 1.378
1 1
309 11602 1- ⁄8 1- ⁄4 1.2535 1.504
5 1
310 16758 1- ⁄8 1- ⁄4 1.2535 1.504
7 1
311 19336 1- ⁄8 1- ⁄4 1.2535 1.504
312 10313 1 1- ⁄4 1.2535 1.630
1 1
313 11602 1- ⁄8 1- ⁄4 1.2535 1.630
1 1
314 12891 1- ⁄4 1- ⁄4 1.2535 1.630
1 1
315 15469 1- ⁄2 1- ⁄4 1.2535 1.630
5 1
316 16758 1- ⁄8 1- ⁄4 1.2535 1.630
3 1
317 18047 1- ⁄4 1- ⁄4 1.2535 1.630
7 1
318 19336 1- ⁄8 1- ⁄4 1.2535 1.630
319 20625 2 1- ⁄4 1.253
...