ASTM D6138-23a

Standard Test Method for Determination of Corrosion-Preventive Properties of Lubricating Greases Under Dynamic Wet Conditions (Emcor Test)

SIGNIFICANCE AND USE
5.1 This test method is used to assess the ability of grease to prevent corrosion in rolling bearings operated in the presence of distilled water, sodium chloride solution, or synthetic sea water. It is used for development and specification purposes.
SCOPE
1.1 This test method covers the determination of corrosion-preventive properties of greases using grease-lubricated ball bearings under dynamic wet conditions.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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: 30-Jun-2023
• ICS: 75.100 - Lubricants, industrial oils and related products
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.G0.06 - Functional Tests - Contamination

Relations

• Refers: ASTM D4175-23a - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 15-Dec-2023
• Refers: ASTM D665-23 - Standard Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of Water
• Effective Date: 01-Dec-2023
• Refers: ASTM D4175-23e1 - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Jul-2023
• Refers: ASTM D665-19 - Standard Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of Water
• Effective Date: 01-Dec-2019
• Refers: ASTM D665-14 - Standard Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of Water
• Effective Date: 01-Oct-2014
• Refers: ASTM D665-12 - Standard Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of Water
• Effective Date: 01-Nov-2012
• Refers: ASTM D665-06 - Standard Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of Water
• Effective Date: 01-May-2006
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D665-03 - Standard Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of Water
• Effective Date: 01-Nov-2003
• Refers: ASTM D665-02 - Standard Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of Water
• Effective Date: 10-Nov-2002
• Refers: ASTM D665-99 - Standard Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of Water
• Effective Date: 10-Dec-1999
• Refers: ASTM D1193-99 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999
• Refers: ASTM D1193-99e1 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999

Overview

ASTM D6138-23a - Standard Test Method for Determination of Corrosion-Preventive Properties of Lubricating Greases Under Dynamic Wet Conditions (Emcor Test) is a crucial method for evaluating the ability of lubricating greases to prevent corrosion in rolling bearings operating under dynamic wet environments. Developed by ASTM International, this standard helps manufacturers, formulators, and users to assess the anti-corrosion performance of greases in the presence of distilled water, sodium chloride solution, or synthetic sea water. This Emcor Test is widely referenced in lubricant specification and quality control processes, supporting the development and selection of greases suitable for challenging industrial conditions.

Key Topics

• Scope and Significance:

  • Assesses the corrosion-preventive properties of lubricating greases in ball bearings under conditions simulating real-world wet environments.
  • Supports formulation, specification, and quality assurance of industrial and automotive lubricants.

• Test Method Overview:

  • Uses grease-lubricated, double row self-aligning ball bearings partially immersed in water-based solutions during dynamic operation.
  • Bearings are examined and rated for corrosion after exposure, following a controlled sequence of running and stopping.

• Corrosion Evaluation:

  • Degree of corrosion is visually inspected and classified from 0 (no corrosion) to 5 (severe corrosion).
  • Only rust or black stains are considered corrosion; superficial stains revealing visible metal are ignored.

• Standardized Conditions:

  • The procedure is performed with specific water types (distilled, sodium chloride solution, or synthetic sea water) and under defined temperatures and operational profiles.

• Safety and Compliance:

  • Users must implement appropriate safety, health, and environmental practices and comply with applicable regulatory requirements.

Applications

ASTM D6138-23a finds practical use in numerous industries where lubricated bearings are exposed to moisture, including:

• Industrial Machinery:

  • Ensures that greases employed in equipment such as pumps, conveyors, and electric motors offer durable protection against corrosion in humid processes or washdown environments.

• Automotive & Transportation:

  • Specifies or verifies bearing greases for vehicles operating in wet or marine climates, minimizing bearing failure and improving reliability.

• Marine & Offshore Equipment:

  • Certifies that marine-grade greases can effectively protect critical rotating components from saltwater-induced corrosion.

• Quality Control & Product Development:

  • Integrates into routine laboratory screening during formulation or batch testing to maintain performance standards required by end users.

Utilizing this test method reduces the risk of equipment downtime, maintenance costs, and potential failures caused by bearing corrosion, driving higher operational efficiency across industries.

Related Standards

Organizations often use ASTM D6138-23a alongside related standards to ensure comprehensive lubricant performance evaluation. Important references include:

• ASTM D217: Test Methods for Cone Penetration of Lubricating Grease.
• ASTM D665: Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of Water.
• ASTM D1193: Specification for Reagent Water.
• ASTM D4175: Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants.
• ISO 15: Rolling bearings - Radial bearings - Boundary dimensions.
• ISO 3696: Water for analytical laboratory use - Specifications and test methods.
• ISO 7120: Petroleum products and lubricants - Determination of rust-preventing characteristics in the presence of water.
• IP 530: Determination of the density of grease by density cup method.

By following ASTM D6138-23a in conjunction with these related standards, lubricant producers and end users can ensure that products meet rigorous international corrosion-preventive performance requirements.

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: D6138 − 23a
Standard Test Method for
Determination of Corrosion-Preventive Properties of
Lubricating Greases Under Dynamic Wet Conditions (Emcor
Test)
This standard is issued under the fixed designation D6138; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* ISO 3696 Water for analytical laboratory use—
Specifications and test methods
1.1 This test method covers the determination of corrosion-
ISO 7120 Petroleum products and lubricants—Petroleum
preventive properties of greases using grease-lubricated ball
oils and other fluids—Determination of rust-preventing
bearings under dynamic wet conditions.
characteristics in the presence of water
1.2 The values stated in SI units are to be regarded as
2.3 EI Standards:
standard. No other units of measurement are included in this
IP 530 Determination of the density of grease—Density cup
standard.
method
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Terminology
responsibility of the user of this standard to establish appro-
3.1 Definitions:
priate safety, health, and environmental practices and deter-
3.1.1 For definitions of terms used in this test method, refer
mine the applicability of regulatory limitations prior to use.
to Terminology D4175.
1.4 This international standard was developed in accor-
3.1.2 corrosion, n—the chemical or electrochemical reac-
dance with internationally recognized principles on standard-
tion between a material, usually a metal, and its environment
ization established in the Decision on Principles for the
that produces a deterioration of the material and its properties.
Development of International Standards, Guides and Recom-
3.1.2.1 Discussion—In this test method, corrosion is mani-
mendations issued by the World Trade Organization Technical
fested by red rust or black stains on the bearing race. Stains,
Barriers to Trade (TBT) Committee.
through which the underlying metal surface is still visible, are
not considered corrosion in Test Method D6138 and shall be
2. Referenced Documents
ignored.
2.1 ASTM Standards:
3.1.3 lubricating grease, n—a semifluid to solid product of
D665 Test Method for Rust-Preventing Characteristics of
a thickener in a liquid lubricant.
Inhibited Mineral Oil in the Presence of Water
3.1.3.1 Discussion—The dispersion of the thickener forms a
D1193 Specification for Reagent Water
two-phase system and immobilizes the liquid lubricant by
D4175 Terminology Relating to Petroleum Products, Liquid
surface tension and other physical forces. Other ingredients are
Fuels, and Lubricants
commonly included to impart special properties.
2.2 ISO Standards:
3.1.4 thickener, n—in lubricating grease, a substance com-
ISO 15 Rolling bearings—Radial bearings—Boundary
posed of finely-divided particles dispersed in a liquid lubricant
dimensions—General plan
to form the product’s structure.
3.1.4.1 Discussion—The thickeners can be fibers (such as
This test method is under the jurisdiction of ASTM Committee D02 on various metallic soaps) or plates or spheres (such as certain
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
non-soap thickener), which are insoluble or, at most, only very
Subcommittee D02.G0.06 on Functional Tests - Contamination.
slightly soluble in the liquid lubricant. The general require-
Current edition approved July 1, 2023. Published July 2023. Originally approved
ments are that the solid particles be extremely small, uniformly
in 1997. Last previous edition approved in 2023 as D6138 – 23. DOI: 10.1520/
D6138-23A.
dispersed, and capable of forming a relatively stable, gel-like
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
structure with the liquid lubricant.
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.
3 4
Available from American National Standards Institute (ANSI), 25 W. 43rd St., Available from Energy Institute, 61 New Cavendish St., London, W1G 7AR,
4th Floor, New York, NY 10036, http://www.ansi.org. U.K., http://www.energyinst.org.
*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
D6138 − 23a
NOTE 1—Other water types, such as that specified in Specification
4. Summary of Test Method
D1193, Type III, or other salt solutions and salt concentrations can be used
4.1 New, cleaned, and lubricated bearings are tested par-
in this test method, although the precision when using other water types
tially immersed in water (distilled, synthetic sea water, or
and salt solutions has not been determined. It is recommended that the pH
of the other water types is determined before use.
sodium chloride solution) under no applied load at a speed of
83 r ⁄min 6 5 r ⁄min in a predetermined sequence of running
7.5 Isopropyl Alcohol—(Warning—Flammable. Poison.
and stopping for a period of approximately one week. After
Causes burns. Vapor extremely irritating. May be fatal if
cleaning, the bearing rings are examined and rated according to
swallowed. Harmful if inhaled.)
the degree of corrosion.
7.6 Ammonium Hydroxide—(Warning—Flammable. Poi-
son. Causes burns. Vapor extremely irritating. May be fatal if
5. Significance and Use
swallowed. Harmful if inhaled.)
5.1 This test method is used to assess the ability of grease to
7.7 Solvent Rinse Solution, of the following composition by
prevent corrosion in rolling bearings operated in the presence
volume:
of distilled water, sodium chloride solution, or synthetic sea
7.7.1 90 % Isopropyl alcohol.
water. It is used for development and specification purposes.
7.7.2 9 % Distilled water.
6. Apparatus 7.7.3 1 % Ammonium hydroxide, 3.2 mol ⁄L concentration.
(Warning—Flammable. Poison. Causes burns. Vapor ex-
6.1 Test Bearings—Use a double row self-aligning ball
tremely irritating. May be fatal if swallowed. Harmful if
bearing (30 mm by 72 mm by 19 mm), conforming to 1306 K
inhaled.)
of ISO 15, with a steel cage. In cases of dispute, the SKF
bearing specified in Footnote 5 shall be used as the referee 7.8 Mineral Spirit, also known as Stoddard Solvent, reagent
bearing.
grade. (Warning—Combustible. Vapor Harmful.)
6.2 SKF TMG/Emcor Test Machine, see Annex A1 for
8. Preparation of Bearings
description.
8.1 Examine the test bearings carefully and select only
6.3 Dentist’s Mirror, non-magnifying.
bearings that have outer rings and balls entirely free of
6.4 Graduated Pipette or Syringe, capable of measuring
corrosion. During the bearing preparation, handle the bearings
20 mL 6 1 mL water.
with tongs or protective gloves. Do not touch the bearings with
6.5 Oven, capable of maintaining 90 °C 6 2 °C.
bare fingers at any time. Use two new bearings for each grease
being tested.
7. Reagents
8.2 Number bearings on the outside diameter of the outer
7.1 Purity of Reagents—Reagent grade chemicals shall be
ring, but do not use chemical etching. One method to number
used in all tests. Unless otherwise indicated, it is intended that
the bearings is with an electric pen, which should be grounded
all reagents shall conform to the specifications of the Commit-
on the outer ring surface being marked.
tee on Analytical Reagents of the American Chemical Society,
6 8.3 Wash the selected bearings thoroughly in hot (50 °C to
where such specifications are available. Other grades may be
65 °C) mineral spirits (Warning—see 7.8) to remove the rust
used, provided it is first ascertained that the reagent is of
preventive. To ensure complete removal, subject the bearing to
sufficiently high purity to permit its use without lessening the
a second wash in fresh hot mineral spirits. (Warning—The
accuracy of the determination.
washing temperatures specified are considerably above the
7.2 Purity of Water—Unless otherwise indicated, references
flash point of the solvent. Accordingly, the washing operation
to water shall be understood to mean freshly boiled double
should be carried out in a well-ventilated hood where no
distilled water, water conforming to Specification D1193 Type
ignition source is present.)
II, or reagent water as defined by Grade 2 of ISO 3696.
NOTE 2—The purpose of the two washes with hot mineral spirits in 8.3
is to completely remove the rust preventative applied to the bearings for
7.3 Synthetic Sea Water—If required, as specified in Test
storage. The duration of the washes required to remove this preventative
Method D665, and ISO 7120.
will be dependent on the equipment used by the lab and the type and
amount of rust preventative applied by the bearing manufacturer. It is
7.4 Sodium Chloride Solution—a 0.5 mol ⁄L solution of
recommended to visually inspect each bearing to assure the rust preven-
sodium chloride prepared using freshly boiled double distilled
tative is removed before proceeding to 8.4. If rust preventative is still
water, water conforming to Specification D1193 Type II, or
present after two washes, the bearings should be washed again in the hot
water conforming to Grade 2 of ISO 3696, at a pH of 8.0 to 8.2
mineral spirits until the bearings are clean and free of residue.
adjusted by titration with sodium hydroxide solution.
8.4 Transfer bearings to the solvent rinse solution
(Warning—see 7.7.3) to remove any mineral spirits which
1306 K steel caged bearing manufactured by NTN and DKF may be used;
may be present. Rinse each bearing and slowly rotate one ring
however, precision had only been evaluated using SKF 1306 K/236 725 bearings.
relative to the other ring in fresh hot (65 °C 6 5 °C) solvent
ACS Reagent Chemicals, Specifications and Procedures for Reagents and
rinse solution. Fresh rinse solution is used to avoid the
Standard-Grade Reference Materials, American Chemical Society, Washington,
selective evaporation of the components at the rinse tempera-
DC. For suggestions on the testing of reagents not listed by the American Chemical
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
ture.
U.K., and the United Stat
...

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: D6138 − 23 D6138 − 23a
Standard Test Method for
Determination of Corrosion-Preventive Properties of
Lubricating Greases Under Dynamic Wet Conditions (Emcor
Test)
This standard is issued under the fixed designation D6138; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This test method covers the determination of corrosion-preventive properties of greases using grease-lubricated ball bearings
under dynamic wet conditions.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.4 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:
D217 Test Methods for Cone Penetration of Lubricating Grease
D665 Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of Water
D1193 Specification for Reagent Water
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
2.2 ISO Standards:
ISO 15 Rolling bearings—Radial bearings—Boundary dimensions—General plan
ISO 3696 Water for analytical laboratory use—Specifications and test methods
ISO 7120 Petroleum products and lubricants—Petroleum oils and other fluids—Determination of rust-preventing characteristics
in the presence of water
2.3 EI Standards:
IP 530 Determination of the density of grease—Density cup method
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.G0.06 on Functional Tests - Contamination.
Current edition approved May 1, 2023July 1, 2023. Published July 2023. Originally approved in 1997. Last previous edition approved in 20192023 as
D6138 – 19.D6138 – 23. DOI: 10.1520/D6138-23.10.1520/D6138-23A.
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 American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Available from Energy Institute, 61 New Cavendish St., London, W1G 7AR, U.K., http://www.energyinst.org.
*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
D6138 − 23a
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology D4175.
3.1.2 corrosion, n—the chemical or electrochemical reaction between a material, usually a metal, and its environment that
produces a deterioration of the material and its properties.
3.1.2.1 Discussion—
In this test method, corrosion is manifested by red rust or black stains on the bearing race. Stains, through which the underlying
metal surface is still visible, are not considered corrosion in Test Method D6138 and shall be ignored.
3.1.3 lubricating grease, n—a semifluid to solid product of a thickener in a liquid lubricant.
3.1.3.1 Discussion—
The dispersion of the thickener forms a two-phase system and immobilizes the liquid lubricant by surface tension and other
physical forces. Other ingredients are commonly included to impart special properties. D217
3.1.4 thickener, n—in lubricating grease, a substance composed of finely-divided particles dispersed in a liquid lubricant to form
the product’s structure.
3.1.4.1 Discussion—
The thickeners can be fibers (such as various metallic soaps) or plates or spheres (such as certain non-soap thickener), which are
insoluble or, at most, only very slightly soluble in the liquid lubricant. The general requirements are that the solid particles be
extremely small, uniformly dispersed, and capable of forming a relatively stable, gel-like structure with the liquid lubricant. D217
3.2 Definitions of Terms Specific to This Standard:
3.2.1 corrosion, n—reddish rust or black spots on the race.
3.2.1.1 Discussion—
Any stain through which the underlying metal surface is still visible shall be ignored.
4. Summary of Test Method
4.1 New, cleaned, and lubricated bearings are tested partially immersed in water (distilled, synthetic sea water, or sodium chloride
solution) under no applied load at a speed of 83 r ⁄min 6 5 r ⁄min in a predetermined sequence of running and stopping for a period
of approximately one week. After cleaning, the bearing rings are examined and rated according to the degree of corrosion.
5. Significance and Use
5.1 This test method is used to assess the ability of grease to prevent corrosion in rolling bearings operated in the presence of
distilled water, sodium chloride solution, or synthetic sea water. It is used for development and specification purposes.
6. Apparatus
6.1 Test Bearings—Use a double row self-aligning ball bearing (30 mm by 72 mm by 19 mm), conforming to 1306 K of ISO 15,
with a steel cage. In cases of dispute, the SKF bearing specified in Footnote 5 shall be used as the referee bearing.
6.2 SKF TMG/Emcor Test Machine, see Annex A1 for description.
6.3 Dentist’s Mirror, non-magnifying.
6.4 Graduated Pipette or Syringe, capable of measuring 20 mL 6 1 mL water.
6.5 Oven, capable of maintaining 90 °C 6 2 °C.
1306 K steel caged bearing manufactured by NTN and DKF may be used; however, precision had only been evaluated using SKF 1306 K/236 725 bearings.
D6138 − 23a
7. Reagents
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where
such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high
purity to permit its use without lessening the accuracy of the determination.
7.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean freshly boiled double distilled
water, water conforming to Specification D1193 Type II, or reagent water as defined by Grade 2 of ISO 3696.
7.3 Synthetic Sea Water—If required, as specified in Test Method D665, and ISO 7120.
7.4 Sodium Chloride Solution—a 0.5 mol ⁄L solution of sodium chloride prepared using freshly boiled double distilled water, water
conforming to Specification D1193 Type II, or water conforming to Grade 2 of ISO 3696, at a pH of 8.0 to 8.2 adjusted by titration
with sodium hydroxide solution.
NOTE 1—Other water types, such as that specified in Specification D1193, Type III, or other salt solutions and salt concentrations can be used in this test
method, although the precision when using other water types and salt solutions has not been determined. It is recommended that the pH of the other water
types is determined before use.
7.5 Isopropyl Alcohol—(Warning—Flammable. Poison. Causes burns. Vapor extremely irritating. May be fatal if swallowed.
Harmful if inhaled.)
7.6 Ammonium Hydroxide—(Warning—Flammable. Poison. Causes burns. Vapor extremely irritating. May be fatal if swallowed.
Harmful if inhaled.)
7.7 Solvent Rinse Solution, of the following composition by volume:
7.7.1 90 % Isopropyl alcohol.
7.7.2 9 % Distilled water.
7.7.3 1 % Ammonium hydroxide, 3.2 mol ⁄L concentration. (Warning—Flammable. Poison. Causes burns. Vapor extremely
irritating. May be fatal if swallowed. Harmful if inhaled.)
7.8 Mineral Spirit, also known as Stoddard Solvent, reagent grade. (Warning—Combustible. Vapor Harmful.)
8. Preparation of Bearings
8.1 Examine the test bearings carefully and select only bearings that have outer rings and balls entirely free of corrosion. During
the bearing preparation, handle the bearings with tongs or protective gloves. Do not touch the bearings with bare fingers at any
time. Use two new bearings for each grease being tested.
8.2 Number bearings on the outside diameter of the outer ring, but do not use chemical etching. One method to number the
bearings is with an electric pen, which should be grounded on the outer ring surface being marked.
8.3 Wash the selected bearings thoroughly in hot (50 °C to 65 °C) mineral spirits (Warning—see 7.8) to remove the rust
preventive. To ensure complete removal, subject the bearing to a second wash in fresh hot mineral spirits. (Warning—The washing
temperatures specified are considerably above the flash point of the solvent. Accordingly, the washing operation should be carried
out in a well-ventilated hood where no ignition source is present.)
ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference Materials, American Chemical Society, Washington, DC. For
suggestions on the testing of reagents not listed by the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and
the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
D6138 − 23a
FIG. 1 Partial Outer Ring of Double-Row Self-Aligning Bearing
NOTE 2—The purpose of the two washes with hot mineral spirits in 8.3 is to completely remove the rust preventative applied to the bearings for storage.
The duration of the washes required to remove this preventative will be dependent on the equipment used by the lab and the type and amount of rust
preventative applied by the bearing manufacturer. It is recommended to visually inspect each bearing to assure the rust preventative is removed before
proceeding to 8.4. If rust preventative is still present after two washes, the bearings should be washed again in the hot mineral sp
...