ASTM D4048-22

Standard Test Method for Detection of Copper Corrosion from Lubricating Grease

SIGNIFICANCE AND USE
5.1 This test method measures the tendency of lubricating grease to corrode copper under specific static conditions. It may be of some value in predicting possible chemical attack on lubricated parts, such as bearings that contain copper or copper alloys. Such corrosion, for example, can cause premature bearing failures. However, no correlations with actual field service, most of which are under dynamic conditions, have been established. It does not measure either the ability of the lubricant to inhibit copper corrosion caused by factors other than the lubricant itself nor does it measure the stability of the grease in the presence of copper.
Note 1: Because this test method requires the ability to determine subtle differences in color of copper strips, persons with certain types of color blindness may find it difficult to accurately compare a test strip to the Copper Strip Corrosion Standard.
SCOPE
1.1 This test method covers the detection of the corrosiveness to copper of lubricating grease.  
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific warning statements, see Sections 7, 8, and 10.  
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: 14-Aug-2022
• ICS: 75.100 - Lubricants, industrial oils and related products
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.G0.01 - Chemical and General Laboratory Tests

Relations

• Refers: ASTM D4175-23a - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 15-Dec-2023
• Refers: ASTM D4175-23e1 - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Jul-2023
• Refers: ASTM D2500-16 - Standard Test Method for Cloud Point of Petroleum Products
• Effective Date: 01-Jan-2016
• Refers: ASTM D97-12 - Standard Test Method for Pour Point of Petroleum Products
• Effective Date: 01-Dec-2012
• Refers: ASTM D97-11 - Standard Test Method for Pour Point of Petroleum Products
• Effective Date: 01-Jun-2011
• Refers: ASTM D130-10 - Standard Test Method for Corrosiveness to Copper from Petroleum Products by Copper Strip Test
• Effective Date: 01-Nov-2010
• Refers: ASTM D97-09 - Standard Test Method for Pour Point of Petroleum Products
• Effective Date: 15-Apr-2009
• Refers: ASTM D2500-09 - Standard Test Method for Cloud Point of Petroleum Products
• Effective Date: 15-Apr-2009
• Refers: ASTM D97-08 - Standard Test Method for Pour Point of Petroleum Products
• Effective Date: 01-Sep-2008
• Refers: ASTM D97-07 - Standard Test Method for Pour Point of Petroleum Products
• Effective Date: 01-Dec-2007
• Refers: ASTM D97-06 - Standard Test Method for Pour Point of Petroleum Products
• Effective Date: 01-Nov-2006
• Refers: ASTM D2500-05 - Standard Test Method for Cloud Point of Petroleum Products
• Effective Date: 01-Jul-2005
• Refers: ASTM D97-05a - Standard Test Method for Pour Point of Petroleum Products
• Effective Date: 01-Jul-2005
• Refers: ASTM D97-05 - Standard Test Method for Pour Point of Petroleum Products
• Effective Date: 01-Jun-2005
• Refers: ASTM D130-04e1 - Standard Test Method for Corrosiveness to Copper from Petroleum Products by Copper Strip Test
• Effective Date: 01-May-2004

Overview

ASTM D4048-22: Standard Test Method for Detection of Copper Corrosion from Lubricating Grease is a recognized method developed by ASTM International for assessing the tendency of lubricating grease to corrode copper under specific laboratory conditions. The presence of copper corrosion indicates the potential chemical reactivity of the grease with copper-containing components, such as bearings, which can lead to premature equipment failures.

This test method provides a standardized approach for manufacturers, suppliers, and users of lubricating greases to evaluate the risk of copper corrosion and ensure product compatibility and reliability for various industrial and automotive applications.

Key Topics

• Copper Corrosion: Evaluates the potential chemical attack on copper or copper alloys immersed in lubricating grease under controlled static conditions.
• Standardized Procedure: Involves fully immersing a prepared copper strip in a sample of lubricating grease, heating it at specified parameters, and comparing the resulting corrosion to a standardized Copper Strip Corrosion Standard.
• Interpretation: The degree of copper tarnish and corrosion is classified visually by direct comparison with color reference standards. The test requires accurate color discrimination.
• Limitation: The method measures corrosion under static conditions-results may not directly correlate with performance under dynamic, real-world service conditions.
• Safety and Handling: Users are responsible for observing proper safety, health, and environmental practices during testing and handling.

Applications

The ASTM D4048-22 standard is widely used in the lubricants industry to:

• Predict Potential Damage: Identify lubricating greases likely to cause copper corrosion, preventing premature failure of copper-containing components (e.g., bearings) in machinery.
• Quality Control: Serve as a quality assurance tool for grease manufacturers to ensure compliance with specified corrosion limits.
• Comparative Evaluation: Compare the corrosion resistance of different lubricating grease formulations and additives aimed at reducing copper attack.
• Material Compatibility Assessments: Aid in the screening of lubricating products for suitability in applications where copper alloys are present.
• Specification and Procurement: Provide a basis for technical specification in procurement contracts and ensure supplied products meet required anti-corrosion standards.

Industries making use of this standard include automotive, industrial machinery, power generation, marine, and any other sectors where copper or its alloys are present in lubricated assemblies.

Related Standards

ASTM D4048-22 references and relates to several other ASTM standards that assess different aspects of lubricants:

• ASTM D130: Test Method for Corrosiveness to Copper from Petroleum Products by Copper Strip Test
• ASTM D97: Test Method for Pour Point of Petroleum Products
• ASTM D2500: Test Method for Cloud Point of Petroleum Products and Liquid Fuels
• ASTM D4175: Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants

These related standards provide additional guidance for evaluating lubricants' physical and chemical characteristics, expanding the framework for comprehensive lubricant testing and specification.

Summary

ASTM D4048-22 is an essential test method for the oil and grease industry, enabling detection and classification of copper corrosion from lubricating grease. By implementing this standard, manufacturers and end-users can effectively minimize the risks of equipment failure due to copper corrosion, optimize grease formulations, and ensure the reliable operation of copper-containing components. The method complements other lubricant testing standards, contributing to a holistic approach to lubricant quality and compatibility evaluation.

Keywords: copper corrosion, lubricating grease, ASTM D4048-22, copper strip test, lubricant compatibility, grease testing, bearing protection, ASTM lubricant standards

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: D4048 − 22
Standard Test Method for
Detection of Copper Corrosion from Lubricating Grease
This standard is issued under the fixed designation D4048; 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* 3. Terminology
1.1 This test method covers the detection of the corrosive- 3.1 Definitions—See Terminology D4175.
ness to copper of lubricating grease.
3.2 copper corrosion, n—effect of a chemical attack on
coppermetalbyalubricantcausingvariouslevelsoftarnishing
1.2 The values stated in SI units are to be regarded as
and change in appearance.
standard. The values given in parentheses after SI units are
3.2.1 Discussion—Acidic and other aggressive species, of-
provided for information only and are not considered standard.
ten sulfur-based, in a lubricant can attack copper or copper
1.3 This standard does not purport to address all of the
alloys present in bearings or other lubricated surfaces. The
safety concerns, if any, associated with its use. It is the
presence of this antagonistic interaction is often apparent in a
responsibility of the user of this standard to establish appro-
well-defined series of color changes.
priate safety, health, and environmental practices and deter-
3.3 lubricant, n—any material interposed between two sur-
mine the applicability of regulatory limitations prior to use.
faces that reduces the friction or wear between them.
For specific warning statements, see Sections 7, 8, and 10.
1.4 This international standard was developed in accor-
3.4 lubricating grease, n—a semi-fluid to solid product of a
dance with internationally recognized principles on standard-
dispersion of a thickener in a liquid lubricant.
ization established in the Decision on Principles for the
3.4.1 Discussion—The dispersion of the thickener forms a
Development of International Standards, Guides and Recom-
two-phase system and immobilizes the liquid lubricant by
mendations issued by the World Trade Organization Technical
surface tension and other physical forces. Other ingredients are
Barriers to Trade (TBT) Committee.
commonly included to impart special properties.
2. Referenced Documents
4. Summary of Test Method
2.1 ASTM Standards:
4.1 Aprepared copper strip is totally immersed in a sample
D97 Test Method for Pour Point of Petroleum Products
of grease and heated in an oven or liquid bath at a specified
D130 Test Method for Corrosiveness to Copper from Petro-
temperature for a definite period of time. Commonly used
leum Products by Copper Strip Test
conditions are 100 °C 6 1 °C (212 °F 6 2 °F) for 24 h 6
D2500 Test Method for Cloud Point of Petroleum Products
5 min. At the end of this heating period, the strip is removed,
and Liquid Fuels
washed, and compared with the Copper Strip Corrosion Stan-
D4175 Terminology Relating to Petroleum Products, Liquid
dard.
Fuels, and Lubricants
5. Significance and Use
2.2 ASTM Adjuncts:
Copper Strip Corrosion Standard
5.1 This test method measures the tendency of lubricating
grease to corrode copper under specific static conditions. It
maybeofsomevalueinpredictingpossiblechemicalattackon
This test method is under the jurisdiction of ASTM Committee D02 on
lubricated parts, such as bearings that contain copper or copper
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
alloys. Such corrosion, for example, can cause premature
Subcommittee D02.G0.01 on Chemical and General Laboratory Tests.
bearing failures. However, no correlations with actual field
Current edition approved Aug. 15, 2022. Published September 2022. Originally
published in 1981. Last previous edition approved in 2019 as D4048 – 19a. DOI:
service, most of which are under dynamic conditions, have
10.1520/D4048-22.
been established. It does not measure either the ability of the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
lubricant to inhibit copper corrosion caused by factors other
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
than the lubricant itself nor does it measure the stability of the
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
grease in the presence of copper.
Available from ASTM International Headquarters. Order Adjunct No.
ADJD0130. Originally produced in 1973. NOTE 1—Because this test method requires the ability to determine
*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
D4048 − 22
subtle differences in color of copper strips, persons with certain types of
7. Reagents and Materials
colorblindnessmayfinditdifficulttoaccuratelycompareateststriptothe
7.1 Acetone—American Chemical Society Reagent-Grade
Copper Strip Corrosion Standard.
acetone is suitable. (Warning—Extremely flammable. Harm-
6. Apparatus ful if inhaled. Vapors may cause flash fires.)
7.2 Copper Strips—Use strips 12.5 mm 6 2mm ( ⁄2 in. 6
6.1 Test Containers—Containers with a minimum width of
1 1 1
24 mm and at least 85 mm tall (sufficient depth to allow the ⁄16 in.) wide, 1.5 mm to 3.0 mm ( ⁄16 in. to ⁄8 in.) thick, cut
75 mm 6 5mm (3in. 6 ⁄4 in.) long from smooth-surfaced,
complete insertion of the copper test strip), made of glass or
other inert material. hard-temper,cold-finishedcopperof99.9+ %purity;electrical
bus bar stock is generally suitable. (See Appendix X1 on
6.2 Test Container Covers—Any small porcelain or glazed
Optional Useful Equipment in Test Method D130.) The strips
silica crucibles or crucible covers or watch glasses or vented
may be used repeatedly but should be discarded when the
corks that lightly cover the test containers, allowing pressure
surfaces become deformed on handling.
equalization between the inside and outside of the containers,
7.3 Polishing Materials—Silicon carbide grit paper of vary-
yet minimizing exposure of the inside of the containers to
ingdegreesoffineness,including65 µm(220 gritCAMI-grade
foreign vapors present in the oven will also be satisfactory.
or P220 FEPA-grade) paper or cloth, also a supply of 105 µm
6.3 Oven—A circulating air oven or liquid bath capable of
(120 grit to 150 grit CAMI-grade or P120 to P150 FEPA-
maintaining a temperature of 100 °C 6 1 °C (212 °F 6 2 °F)
grade) silicon carbide grain and absorbent cotton (cotton
or other desired temperatures with the same precision.
wool).
6.4 Polishing Vise—For holding the copper strip firmly
7.4 Wash Solvent—Volatile, sulfur-free hydrocarbon solvent
without marring the edges while polishing. Any convenient
maybeusedprovidedthatitshowsnotarnishatallwhentested
type of holder (see Appendix X1 on Optional Useful Equip-
at 50 °C 6 1 °C (or 122 °F 6 2 °F). Knock test-grade
ment in Test Method D130) may be used, provided that the
isooctane (Warning—see 8.1.2) or American Chemical Soci-
strip is held tightly and that the surface of the strip being
ety Reagent-Grade n-heptane (Warning—see 7.1) are suitable
polished is supported above the surface of the holder.
solvents. Because of possible toxic effects, the use of benzene
6.5 Viewing Test Tubes—Flat glass test tubes may be used to
should be avoided.
protect corroded strips for close inspection or storage. (See
Appendix X1 on Optional Useful Equipment in Test Method
8. Preparation of Strip
D130.)
8.1 Mechanical Cleaning of Strips:
6.6 Copper Strip Corrosion Standard—Consists of repro-
8.1.1 Surface Preparation—Remove all surface blemishes
ductions in color of typical strips representing degrees of
from all six sides of the strip with silicon carbide paper of such
tarnish and corrosion, the reproductions being encased in
degrees of fineness as are needed to accomplish the desired
plastic in the form of a plaque.
results efficiently (see Note 2). Finish with 65 µm (220 grit
6.6.1 Keep the plastic-encased printed Copper Strip Corro-
CAMI-grade or P220 FEPA-grade) silicon carbide paper or
sion Standard protected from light to avoid the possibility of
cloth, removing all marks that may have been made by other
fading. Inspect for fading by comparing two different plaques,
grades of paper used previously. Immerse the strip in wash
one of which has been carefully protected from light (new).
solvent (Warning—see 7.1.) from which it can be withdrawn
Observe both sets in diffused daylight (or equivalent), first
immediately for final polishing or in which it can be stored for
from a point directly above and then from an angle of
future use.
approximately 45°. If any evidence of fading is observed,
NOTE 2—Only final preparation (8.1.2) is necessary for commercially
particularly at the left end of the plaque, it is suggested that the
purchased pre-polished strips. Statistical evaluation involving pre-
one that is the more faded with respect to the other be
polished copper strips has been performed using gasoline sample types
discarded.
(see Test Method D130). The recommendation for grease is based on this
6.6.1.1 Alternatively, place a 20 mm ( ⁄4 in.) opaque strip
evaluation, as well as additional data generated by Subcommittee
D02.G0.01 and the technical judgment of its members.
(masking tape) across the top of the colored portion of the
plaque when initially purchased. At intervals, remove the
8.1.1.1 As a practical manual procedure for surface
opaque strip and observe. If there is any evidence of fading of
preparation,placeasheetofthepaperonaflatsurface,moisten
the exposed portion, it is suggested that the standard be
it with wash solvent, and rub the strip against the paper with a
replaced.
rotarymotion,protectingthestripfromcontactwiththefingers
6.6.1.2 These plaques are full-color productions of typical
or by wearing impervious gloves (see Note 3). Alternatively,
strips. They have been printed on photolithographed strips and
the surface of the strip may be prepared by use of motor-driven
areencasedinplasticforprotection.Directionsfortheiruseare
machines using appropriate grades of dry paper or cloth.
given on the reverse side of each plaque.
NOTE 3—Disposable polyethylene is one type of glove that has been
6.6.2 If the surface of the plastic cover shows excessive
found to be satisfactory. However, any type of glove that is impervious to
scratching, it is suggested that the plaque be replaced.
the reagents and materials used in this test method, while preventing
fingers from contacting the strip directly, may also be used.
6.7 Forceps, with either stainless steel or polytetrafluoro-
ethylene (PTFE) tips, for use in handling the copper strips, 8.1.2 Final Polishing—Removestripf
...

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: D4048 − 19a D4048 − 22
Standard Test Method for
Detection of Copper Corrosion from Lubricating Grease
This standard is issued under the fixed designation D4048; 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 test method covers the detection of the corrosiveness to copper of lubricating grease.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for
information only and are not considered standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use. For specific warning statements, see Sections 7, 8, and 10.
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:
D97 Test Method for Pour Point of Petroleum Products
D130 Test Method for Corrosiveness to Copper from Petroleum Products by Copper Strip Test
D2500 Test Method for Cloud Point of Petroleum Products and Liquid Fuels
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
2.2 ASTM Adjuncts:
Copper Strip Corrosion Standard
3. Terminology
3.1 Definitions—See Terminology D4175.
3.2 copper corrosion, n—effect of a chemical attack on copper metal by a lubricant causing various levels of tarnishing and change
in appearance.
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.G0.01 on Chemical and General Laboratory Tests.
Current edition approved July 1, 2019Aug. 15, 2022. Published September 2019September 2022. Originally published in 1981. Last previous edition approved in 2019
as D4048 – 19.D4048 – 19a. DOI: 10.1520/D4048-19A.10.1520/D4048-22.
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 ASTM International Headquarters. Order Adjunct No. ADJD0130. Originally produced in 1973.
*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
D4048 − 22
3.2.1 Discussion—
Acidic and other aggressive species, often sulfur-based, in a lubricant can attack copper or copper alloys present in bearings or
other lubricated surfaces. The presence of this antagonistic interaction is often apparent in a well-defined series of color changes.
3.3 lubricant, n—any material interposed between two surfaces that reduces the friction or wear between them.
3.4 lubricating grease, n—a semi-fluid to solid product of a dispersion of a thickener in a liquid lubricant.
3.4.1 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.
4. Summary of Test Method
4.1 A prepared copper strip is totally immersed in a sample of grease and heated in an oven or liquid bath at a specified temperature
for a definite period of time. Commonly used conditions are 100 °C 6 1 °C (212 °F 6 2 °F) for 24 h 6 5 min. At the end of this
heating period, the strip is removed, washed, and compared with the Copper Strip Corrosion Standard.
5. Significance and Use
5.1 This test method measures the tendency of lubricating grease to corrode copper under specific static conditions. It may be of
some value in predicting possible chemical attack on lubricated parts, such as bearings that contain copper or copper alloys. Such
corrosion, for example, can cause premature bearing failures. However, no correlations with actual field service, most of which
are under dynamic conditions, have been established. It does not measure either the ability of the lubricant to inhibit copper
corrosion caused by factors other than the lubricant itself nor does it measure the stability of the grease in the presence of copper.
NOTE 1—Because this test method requires the ability to determine subtle differences in color of copper strips, persons with certain types of color
blindness may find it difficult to accurately compare a test strip to the Copper Strip Corrosion Standard.
6. Apparatus
6.1 Test Containers—Containers with a minimum width of 24 mm and at least 85 mm tall (sufficient depth to allow the complete
insertion of the copper test strip), made of glass or other inert material.
6.2 Test Container Covers—Any small porcelain or glazed silica crucibles or crucible covers or watch glasses or vented corks that
lightly cover the test containers, allowing pressure equalization between the inside and outside of the containers, yet minimizing
exposure of the inside of the containers to foreign vapors present in the oven will also be satisfactory.
6.3 Oven—A circulating air oven or liquid bath capable of maintaining a temperature of 100 °C 6 1 °C (212 °F 6 2 °F) or other
desired temperatures with the same precision.
6.4 Polishing Vise—For holding the copper strip firmly without marring the edges while polishing. Any convenient type of holder
(see Appendix X1 on Optional Useful Equipment in Test Method D130) may be used, provided that the strip is held tightly and
that the surface of the strip being polished is supported above the surface of the holder.
6.5 Viewing Test Tubes—Flat glass test tubes may be used to protect corroded strips for close inspection or storage. (See Appendix
X1 on Optional Useful Equipment in Test Method D130.)
6.6 Copper Strip Corrosion Standard—Consists of reproductions in color of typical strips representing degrees of tarnish and
corrosion, the reproductions being encased in plastic in the form of a plaque.
6.6.1 Keep the plastic-encased printed Copper Strip Corrosion Standard protected from light to avoid the possibility of fading.
Inspect for fading by comparing two different plaques, one of which has been carefully protected from light (new). Observe both
sets in diffused daylight (or equivalent), first from a point directly above and then from an angle of approximately 45°. If any
evidence of fading is observed, particularly at the left end of the plaque, it is suggested that the one that is the more faded with
respect to the other be discarded.
D4048 − 22
6.6.1.1 Alternatively, place a 20 mm ( ⁄4 in.) opaque strip (masking tape) across the top of the colored portion of the plaque when
initially purchased. At intervals, remove the opaque strip and observe. If there is any evidence of fading of the exposed portion,
it is suggested that the standard be replaced.
6.6.1.2 These plaques are full-color productions of typical strips. They have been printed on photolithographed strips and are
encased in plastic for protection. Directions for their use are given on the reverse side of each plaque.
6.6.2 If the surface of the plastic cover shows excessive scratching, it is suggested that the plaque be replaced.
6.7 Forceps, with either stainless steel or polytetrafluoroethylene (PTFE) tips, for use in handling the copper strips, have been
found suitable to use.
7. Reagents and Materials
7.1 Acetone—American Chemical Society Reagent-Grade acetone is suitable. (Warning—Extremely flammable. Harmful if
inhaled. Vapors may cause flash fires.)
1 1 1 1
7.2 Copper Strips—Use strips 12.5 mm 6 2 mm ( ⁄2 in. 6 ⁄16 in.) wide, 1.5 mm to 3.0 mm ( ⁄16 in. to ⁄8 in.) thick, cut 75 mm 6
5 mm (3 in. 6 ⁄4 in.) long from smooth-surfaced, hard-temper, cold-finished copper of 99.9+ % purity; electrical bus bar stock
is generally suitable. (See Appendix X1 on Optional Useful Equipment in Test Method D130.) The strips may be used repeatedly
but should be discarded when the surfaces become deformed on handling.
7.3 Polishing Materials—Silicon carbide grit paper of varying degrees of fineness, including 65 μm (220 grit CAMI-grade or P220
FEPA-grade) paper or cloth, also a supply of 105 μm (120 grit to 150 grit CAMI-grade or P120 to P150 FEPA-grade) silicon
carbide grain and absorbent cotton (cotton wool).
7.4 Wash Solvent—Volatile, sulfur-free hydrocarbon solvent may be used provided that it shows no tarnish at all when tested at
50 °C 6 1 °C (or 122 °F 6 2 °F). Knock test-grade isooctane (Warning—see 8.1.2) or American Chemical Society Reagent-Grade
n-heptane (Warning—see 7.1) are suitable solvents. Because of possible toxic effects, the use of benzene should be avoided.
8. Preparation of Strip
8.1 Mechanical Cleaning of Strips:
8.1.1 Surface Preparation—Remove all surface blemishes from all six sides of the strip with silicon carbide paper of such degrees
of fineness as are needed to accomplish the desired results efficiently (see Note 2). Finish with 65 μm (220 grit CAMI-grade or
P220 FEPA-grade) silicon carbide paper or cloth, removing all marks that may have been made by other grades of paper used
previously. Immerse the strip in wash solvent (Warning—see 7.1.) from which it can be withdrawn immediately for final polishing
or in which it can be stored for future use.
NOTE 2—Only final preparation (8.1.2) is necessary for commercially purchased pre-polished strips. Statistical evaluation involving pre-polished copper
strips has been performed using gasoline sample types (see Test Method D130). The recommendation for grease is based on this evaluation, as well as
additional data generated by Subcommittee D02.G0.01 and the technical judgment of its members.
8.1.1.1 As a practical manual procedure for surface preparation, place a sheet of the paper on a flat surface, moisten it with wash
solvent, and rub the strip against the paper with a rotary motion, protecting the strip from contact with the fingers or by wearing
impervious gloves (see Note 3). Alternatively, the surface of the strip may be prepared by use of motor-driven machines using
appropriate grades of dry paper or cloth.
NOTE 3—Disposable polyethylene is one type of glove that has been found to be satisfactory. However, any type of glove that is impervious to the reagents
and materials used in this test method, while preventing fingers from contacting the strip directly, may also be used.
8.1.2 Final Polishing—Remove strip from the wash solvent. Holding it in the fingers protected with the ashless filter paper, polish
first the ends and then the sides with the 105 μm (120 g
...