ASTM D1403-20b

Standard Test Methods for Cone Penetration of Lubricating Grease Using One-Quarter and One-Half Scale Cone Equipment

SIGNIFICANCE AND USE
5.1 These test methods are applicable to greases of National Lubricating Grease Institute (NLGI) consistency numbers 0 to 4 and are intended for use only where the size of the sample prevents the use of Test Methods D217.  
5.2 Actual reduced-scale penetration values are not used or reported. They are converted to full-scale penetration values (see Sections 9 and 10). This test method is not intended to replace the full-scale penetration as described in Test Methods D217. Precision is better in the full-scale penetration method.  
5.3 Worked penetration results, after conversion to full-scale values, may be used to establish the consistency of lubricating greases within the above NLGI consistency numbers. The results obtained from these test methods are widely used for specification purposes, however, no correlation with field performance has been established.  
5.4 Unworked reduced-scale penetration results provide a means of evaluating the effect of storage conditions on grease consistency.
SCOPE
1.1 These test methods cover two procedures for measuring the consistency of small samples of lubricating greases by penetration of a 1/4-scale cone or a 1/2-scale cone. These test methods include procedures for the measurement of unworked and worked penetrations.  
1.2 Unworked penetrations do not generally represent the consistency of greases in use as effectively as do worked penetrations. The latter are usually preferred for inspecting lubricating greases.  
1.3 The values in SI units are to be regarded as the standard. The values given in parentheses are for information only. In the United States, the equipment dimensions stated in inches are to be regarded as the standard.  
1.4 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.  
1.5 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-May-2020
• ICS: 75.100 - Lubricants, industrial oils and related products
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.G0.02 - Consistency and Related Rheological Tests

Relations

• Replaces: ASTM D1403-20a - Standard Test Methods for Cone Penetration of Lubricating Grease Using One-Quarter and One-Half Scale Cone Equipment
• Effective Date: 01-Jun-2020
• 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 D217-19a - Standard Test Methods for Cone Penetration of Lubricating Grease
• Effective Date: 01-Jul-2019
• Refers: ASTM D217-19 - Standard Test Methods for Cone Penetration of Lubricating Grease
• Effective Date: 01-May-2019
• Refers: ASTM D217-16 - Standard Test Methods for Cone Penetration of Lubricating Grease
• Effective Date: 01-Oct-2016
• Refers: ASTM D217-10 - Standard Test Methods for Cone Penetration of Lubricating Grease
• Effective Date: 01-May-2010
• Refers: ASTM D217-02(2007) - Standard Test Methods for Cone Penetration of Lubricating Grease
• Effective Date: 01-Nov-2007
• Refers: ASTM D217-02 - Standard Test Methods for Cone Penetration of Lubricating Grease
• Effective Date: 10-Dec-2002
• Referred By: ASTM D4693-07(2021) - Standard Test Method for Low-Temperature Torque of Grease-Lubricated Wheel Bearings
• Effective Date: 01-Jun-2020
• Referred By: ASTM D6185-11(2017) - Standard Practice for Evaluating Compatibility of Binary Mixtures of Lubricating Greases
• Effective Date: 01-Jun-2020
• Referred By: ASTM D1831-21 - Standard Test Method for Roll Stability of Lubricating Grease
• Effective Date: 01-Jun-2020
• Referred By: ASTM D217-21a - Standard Test Methods for Cone Penetration of Lubricating Grease
• Effective Date: 01-Jun-2020
• Referred By: ASTM D8022-20 - Standard Test Method for Roll Stability of Lubricating Grease in Presence of Water (Wet Roll Stability Test)
• Effective Date: 01-Jun-2020
• Referred By: ASTM D3704-96(2017) - Standard Test Method for Wear Preventive Properties of Lubricating Greases Using the (Falex) Block on Ring Test Machine in Oscillating Motion
• Effective Date: 01-Jun-2020

Overview

ASTM D1403-20b: Standard Test Methods for Cone Penetration of Lubricating Grease Using One-Quarter and One-Half Scale Cone Equipment establishes internationally recognized procedures for evaluating the consistency of small samples of lubricating grease. Developed by ASTM International, this standard is particularly useful for lubricating greases with National Lubricating Grease Institute (NLGI) consistency numbers 0 to 4, when the sample size is insufficient for full-scale testing as described in ASTM D217.

This method enables reliable laboratory assessment of grease consistency using reduced-scale (one-quarter and one-half) cones and grease workers. Critical for quality control and specification purposes, these test methods convert reduced-scale results into full-scale penetration values for comparison and reporting. The standard supports industries involved in the production, quality assessment, and research of lubricating greases, especially when only limited material is available.

Key Topics

• Consistency Measurement: Assesses grease consistency by measuring the depth of penetration of a cone under prescribed conditions. Consistency is directly related to grease’s resistance to deformation under mechanical stress.
• Sample Size Limitations: Specifically intended for small sample sizes, where standard cone penetration methods (ASTM D217) cannot be applied.
• Worked and Unworked Penetration:
  • Unworked penetration evaluates the effect of storage conditions on grease consistency.
  • Worked penetration (after mechanical shearing) provides a better representation of greases in actual use and is ideal for specification verification.
• Reduced-Scale Equipment: Utilizes one-quarter and one-half scale cones and workers to perform the penetration test on small grease samples.
• Conversion to Full-Scale Values: Reduced-scale results are mathematically converted to equivalent full-scale penetration values for standardized reporting and compliance.
• Precision and Reporting: Full-scale values are reported, as precision is generally superior in full-scale tests but the reduced-scale method offers practicality and accuracy when sample quantity is limited.

Applications

ASTM D1403-20b is widely used in the lubricants industry for:

• Quality Control: Ensuring batch-to-batch consistency of lubricating greases, even when only small test samples are available.
• Product Development: Supporting R&D teams in evaluating prototype and specialty greases during formulation trials.
• Field Sampling: Providing an effective method for evaluating consistency from limited samples, such as those collected from bearings or field machinery.
• Specification Compliance: Demonstrating compliance with customer or regulatory specifications for lubricating grease consistency, based on internationally recognized procedures.
• Storage Condition Assessment: Using unworked penetration data to monitor changes in grease consistency due to storage or transportation.

These applications are essential in automotive, industrial, aerospace, and marine sectors where lubricating grease consistency impacts equipment reliability and performance.

Related Standards

The following standards and references are closely associated with ASTM D1403-20b:

• ASTM D217: Standard Test Methods for Cone Penetration of Lubricating Grease (full-scale penetration)
• ASTM D4175: Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• IP 50: Energy Institute’s Method of Testing for Cone Penetration of Lubricating Grease

For organizations requiring flexibility in sample sizing and internationally accepted quality control methods, ASTM D1403-20b remains an essential standard for lubricating grease evaluation and testing.

Keywords: ASTM D1403, lubricating grease, cone penetration, reduced-scale test, consistency measurement, NLGI, quality control, worked penetration, unworked penetration, lubricants industry.

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: D1403 − 20b
Designation: 310/84 (92)
Standard Test Methods for
Cone Penetration of Lubricating Grease Using One-Quarter
and One-Half Scale Cone Equipment
This standard is issued under the fixed designation D1403; 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* 2. Referenced Documents
2.1 ASTM Standards:
1.1 These test methods cover two procedures for measuring
D217 Test Methods for Cone Penetration of Lubricating
the consistency of small samples of lubricating greases by
Grease
1 1
penetration of a ⁄4-scale cone or a ⁄2-scale cone. These test
D4175 Terminology Relating to Petroleum Products, Liquid
methods include procedures for the measurement of unworked
Fuels, and Lubricants
and worked penetrations.
2.2 Energy Institute Standard:
1.2 Unworked penetrations do not generally represent the
IP50 Method ofTesting for Cone Penetration of Lubricating
consistency of greases in use as effectively as do worked
Grease
penetrations. The latter are usually preferred for inspecting
3. Terminology
lubricating greases.
3.1 Definitions:
1.3 The values in SI units are to be regarded as the standard.
3.1.1 consistency, n—of lubricating grease, the degree of
Thevaluesgiveninparenthesesareforinformationonly.Inthe
resistance to movement under stress.
United States, the equipment dimensions stated in inches are to
3.1.1.1 Discussion—Thetermconsistencyisusedsomewhat
be regarded as the standard.
synonymously with penetration. Generally, consistency refers
to the worked penetration of a grease. D217
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3.1.2 lubricant, n—any material interposed between two
responsibility of the user of this standard to establish appro-
surfaces that reduces the friction or wear between them. D4175
priate safety, health, and environmental practices and deter-
3.1.3 lubricating grease, n—a semi-fluid to solid product of
mine the applicability of regulatory limitations prior to use.
a dispersion of a thickener in a liquid lubricant.
1.5 This international standard was developed in accor-
3.1.3.1 Discussion—The dispersion of the thickener forms a
dance with internationally recognized principles on standard-
two-phase system and immobilizes the liquid lubricant by
ization established in the Decision on Principles for the
surface tension and other physical forces. Other ingredients
Development of International Standards, Guides and Recom-
imparting special properties are often included. D217
mendations issued by the World Trade Organization Technical
3.1.4 penetration, n—of lubricating grease, the depth that
Barriers to Trade (TBT) Committee.
the standard cone, when released to fall under its own weight
for 5 s, enters the sample.
3.1.5 penetrometer, n—an instrument that measures the
These test methods are under the jurisdiction of ASTM Committee D02 on
consistency or hardness of semiliquid to semisolid materials by
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.G0.02 on Consistency and Related Rheological Tests.
In the IP, this test method is under the jurisdiction of the Standardization For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Committee. This test method has been approved by the sponsoring committee and contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
accepted by the cooperating societies in accordance with established procedures. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved June 1, 2020. Published September 2020. Originally the ASTM website.
approved in 1956. Last previous edition approved in 2020 as D1403 – 20a. DOI:
Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,
10.1520/D1403-20B. U.K., http://www.energyinst.org.uk.
*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
D1403 − 20b
measuring the depth to which a specified cone or needle under 4 and are intended for use only where the size of the sample
a given force falls into the material. prevents the use of Test Methods D217.
3.1.5.1 Discussion—Either a ⁄4-scale cone (A1.1)ora
5.2 Actual reduced-scale penetration values are not used or
⁄2-scale cone (A1.3) can be used to determine the consistency
reported. They are converted to full-scale penetration values
of lubricating greases. The penetration forces are determined
(see Sections 9 and 10). This test method is not intended to
by the respective masses of the cones and shafts.
replace the full-scale penetration as described in Test Methods
3.1.6 reduced-scale penetration, n—of lubricating grease,
D217. Precision is better in the full-scale penetration method.
1 1
the depth in units of 0.1 mm that a ⁄4-scale cone or ⁄2-scale
5.3 Worked penetration results, after conversion to full-
cone penetrates the sample when released to fall under its own
scale values, may be used to establish the consistency of
weight for 5 s.
lubricating greases within the above NLGI consistency num-
3.1.6.1 Discussion—The term reduced-scale penetration is
bers. The results obtained from these test methods are widely
similar to the term penetration found in Test Methods D217.
used for specification purposes, however, no correlation with
However, due to the differences in scale, the terms are not
field performance has been established.
synonymous and should not be confused.
5.4 Unworked reduced-scale penetration results provide a
3.1.7 reduced-scale penetrometer, n—an instrument similar
means of evaluating the effect of storage conditions on grease
to that shown in Fig. 1 of Test Methods D217, designed to
consistency.
measure the consistency or hardness of semi-liquid to semi-
solid materials by measuring the depth to which the ⁄4-scale or
6. Apparatus
the ⁄2-scale cone falls into grease.
6.1 Reduced-Scale Penetrometer—An instrument similar to
3.1.7.1 Discussion—Either a ⁄4-scale cone (A1.1)ora
that shown in Fig. 1 of Test Methods D217, adapted for use
⁄2-scale cone (A1.3) can be used to determine the consistency 1 1
with the ⁄4-scale or ⁄2-scale cone.
oflubricatinggreaseswhenthequantityofsampleavailablefor
NOTE 1—Any slight binding in the instrument may produce a signifi-
testing is limited. The penetration forces are determined by the
cant error in penetration values. Periodic check of the release mechanism,
respective masses of the cones and shafts.
cone dimensions, and weights of cone and its movable attachments is
3.1.8 reduced-scale worked penetration, n—of lubricating
recommended.
grease, the penetration at 25 °C (77 °F), without delay, of a
6.2 ⁄4-Scale Cone and Shaft, as specified in A1.1.
1 1
sample after 60 double strokes in a ⁄4-scale or ⁄2-scale grease
6.3 ⁄4-Scale Grease Worker, as specified in A1.2.
worker.
6.4 ⁄2-Scale Cone and Shaft, as specified in A1.3.
3.1.9 thickener, n—in lubricating grease, a substance com-
posed of finely divided particles dispersed in a liquid lubricant 1
6.5 ⁄2-Scale Grease Worker, as specified in A1.4.
to form the product’s structure.
6.6 Temperature Bath, capable of controlling the bath tem-
3.1.9.1 Discussion—The thickener can be fibers (such as
perature at 25 °C 6 0.5 °C (77 °F 6 1 °F) and designed to
various metallic soaps) or plates or spheres (such as certain
bring the assembled grease worker to test temperature conve-
non-soap thickeners) which are insoluble or, at the most, only
niently.Examplesofsuitabletemperaturebathsincludeawater
very slightly soluble in the liquid lubricant. The general
bath, air bath, constant temperature test room, or a
requirements are that the solid particles be extremely small,
temperature-controlled metal block. If a water bath is to be
uniformlydispersed,andcapableofformingarelativelystable,
used for samples for unworked, reduced-scale penetration,
gel-like structure with the liquid lubricant. D217
means should be provided for protecting the grease surface
3.1.10 unworked penetration, n—the penetration at 25 °C
from water and for maintaining the air above the sample at test
(77 °F) of a sample of lubricating grease that has received only
temperature.An air bath is preferred for bringing block greases
1 1
minimum disturbance in transfer to a ⁄4-scale or ⁄2-scale
to test temperature, but a tightly sealed container placed in a
grease worker cup or dimensionally equivalent rigid container.
water bath will suffice.
3.1.11 worked penetration, n—of lubricating grease, the
6.7 Spatula, corrosion-resistant, having a stiff blade ap-
penetration at 25 °C (77 °F), without delay, of a sample after
proximately 13 mm (0.5 in.) wide and convenient in length.
60 double strokes in a standard grease worker.
3.1.12 working, v—the subjection of a lubricating grease to 7. Procedure for Unworked, Reduced-Scale Penetration
1 1
the shearing action of the ⁄4-scale or ⁄2-scale grease worker.
7.1 Sample—Sufficient sample to overfill the cup of the
grease worker is required. Three measurements can be ob-
4. Summary of Test Method
tained from one filling of the grease cup, by replacement of
4.1 The reduced-scale penetration is determined at 25 °C 6
grease lost to the cone and repairing of the grease surface.
1 1
0.5 °C(77 °F 61 °F)byreleasingthe ⁄4-scaleor ⁄2-scalecone
7.2 Preparing Sample for Measurement—Place the empty
assembly from the penetrometer and allowing the cone to drop
grease worker cup and an appropriate amount of the sample in
freely into the grease for 5 s 6 0.1 s.
a container in the temperature bath maintained at 25 °C 6
5. Significance and Use
0.5 °C (77 °F 6 1 °F) for sufficient time to bring the tempera-
5.1 These test methods are applicable to greases of National tureofthesampleandtheworkercupto25 °C 60.5 °C(77 °F
Lubricating Grease Institute (NLGI) consistency numbers 0 to 6 1 °F). Transfer the sample, preferably in one lump, to
D1403 − 20b
overfill the cup of the grease worker. Make this transfer in such being packed to remove any air inadvertently entrapped.
a manner that the grease will be worked as little as possible. Jar Assemble the worker and, with the vent cock open, depress the
the cup to drive out trapped air and pack the grease with the plunger to the bottom. Close the vent cock and place the
spatula, with as little manipulation as possible to fill the cup assembled worker in the temperature bath maintained at 25 °C
without air pockets. Scrape off the excess grease extending 6 0.5 °C (77 °F 6 1 °F) until the temperature of the worker
above the rim, creating a flat surface, by moving the blade of and contents are at 25 °C 6 0.5 °C (77 °F 6 1 °F). Then
the spatula, held inclined toward the direction of motion at an remove the worker from the bath and wipe off any water
angle of approximately 45°, across the rim of the cup, retaining adheringtoitssurfaces.Ifthegreasesampleandequipmentare
the portion removed. Do not perform any further leveling or already at the correct temperature before the sample is placed
smoothing of the surface throughout the determination of into the worker cup, there is no need to further stabilize the
unworked, reduced-scale penetration and determine the mea- sample once it has been placed in the cup. Subject the grease
surement immediately. to 60 full double strokes of the plunger, completed in 1 min 6
5 s, and return the plunger to its top position. Open the vent
NOTE 2—The jarring should be as vigorous as required to remove the
cock, remove the top and plunger, and return to the cup as
entrapped air without splashing the specimen from the cup. In performing
much of the grease clinging to the plunger as can readily be
these operations, a minimum of manipulation should be used, as any
agitation of the grease can have the effect of applying so
...

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: D1403 − 20a D1403 − 20b
Designation: 310/84 (92)
Standard Test Methods for
Cone Penetration of Lubricating Grease Using One-Quarter
and One-Half Scale Cone Equipment
This standard is issued under the fixed designation D1403; 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 These test methods cover two procedures for measuring the consistency of small samples of lubricating greases by penetration
1 1
of a ⁄4-scale cone or a ⁄2-scale cone. These test methods include procedures for the measurement of unworked and worked
penetrations.
1.2 Unworked penetrations do not generally represent the consistency of greases in use as effectively as do worked penetrations.
The latter are usually preferred for inspecting lubricating greases.
1.3 The values in SI units are to be regarded as the standard. The values given in parentheses are for information only. In the
United States, the equipment dimensions stated in inches are to be regarded as the standard.
1.4 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.
1.5 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
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
2.2 Energy Institute Standard:
IP 50 Method of Testing for Cone Penetration of Lubricating Grease
These test methods are under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.G0.02 on Consistency and Related Rheological Tests.
In the IP, this test method is under the jurisdiction of the Standardization Committee. This test method has been approved by the sponsoring committee and accepted by
the cooperating societies in accordance with established procedures.
Current edition approved April 1, 2020June 1, 2020. Published April 2020September 2020. Originally approved in 1956. Last previous edition approved in 2020 as
D1403 – 20.D1403 – 20a. DOI: 10.1520/D1403-20A.10.1520/D1403-20B.
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 Energy Institute, 61 New Cavendish St., London, WIG 7AR, U.K., http://www.energyinst.org.uk.
*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
D1403 − 20b
3. Terminology
3.1 Definitions:
3.1.1 consistency, n—of lubricating grease, the degree of resistance to movement under stress.
3.1.1.1 Discussion—
The term consistency is used somewhat synonymously with penetration. Generally, consistency refers to the worked penetration
of a grease. D217
3.1.2 lubricant, n—any material interposed between two surfaces that reduces the friction or wear between them. D4175
3.1.3 lubricating grease, n—a semi-fluid to solid product of a dispersion 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 imparting special properties are often included. D217
3.1.4 penetration, n—of lubricating grease, the depth that the standard cone, when released to fall under its own weight for 5 s,
enters the sample.
3.1.5 penetrometer, n—an instrument that measures the consistency or hardness of semiliquid to semisolid materials by measuring
the depth to which a specified cone or needle under a given force falls into the material.
3.1.5.1 Discussion—
1 1
In these test methods, either Either a ⁄4-scale cone (A1.1) or a ⁄2-scale cone (A1.3) can be used to determine the consistency of
lubricating greases. The penetration forces are determined by the respective masses of the cones and shafts.
1 1
3.1.6 reduced-scale penetration, n—of lubricating grease, the depth in units of 0.1 mm that a ⁄4-scale cone or ⁄2-scale cone
penetrates the sample when released to fall under its own weight for 5 s.
3.1.6.1 Discussion—
The term reduced-scale penetration used in these test methods is similar to the term penetration found in Test Methods D217.
However, due to the differences in scale, the terms are not synonymous and should not be confused.
3.1.7 reduced-scale penetrometer, n—an instrument similar to that shown in Fig. 1 of Test Methods D217, designed to measure
1 1
the consistency or hardness of semi-liquid to semi-solid materials by measuring the depth to which the ⁄4-scale or the ⁄2-scale cone
falls into grease.
3.1.7.1 Discussion—
1 1
In these test methods, either Either a ⁄4-scale cone (A1.1) or a ⁄2-scale cone (A1.3) can be used to determine the consistency of
lubricating greases when the quantity of sample available for testing is limited. The penetration forces are determined by the
respective masses of the cones and shafts.
3.1.8 reduced-scale worked penetration, n—of lubricating grease, the penetration at 25 °C (77 °F), without delay, of a sample after
1 1
60 double strokes in a ⁄4-scale or ⁄2-scale grease worker.
3.1.9 thickener, n—in lubricating grease, a substance composed of finely divided particles dispersed in a liquid lubricant to form
the product’s structure.
3.1.9.1 Discussion—
The thickener can be fibers (such as various metallic soaps) or plates or spheres (such as certain non-soap thickeners) which are
insoluble or, at the 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
3.1.10 unworked penetration, n—the penetration at 25 °C (77 °F) of a sample of lubricating grease that has received only
1 1
minimum disturbance in transfer to a ⁄4-scale or ⁄2-scale grease worker cup or dimensionally equivalent rigid container.
3.1.11 worked penetration, n—of lubricating grease, the penetration at 25 °C (77 °F), without delay, of a sample after 60 double
strokes in a standard grease worker.
1 1
3.1.12 working, v—the subjection of a lubricating grease to the shearing action of the ⁄4-scale or ⁄2-scale grease worker.
D1403 − 20b
4. Summary of Test Method
1 1
4.1 The reduced-scale penetration is determined at 25 °C 6 0.5 °C (77 °F 6 1 °F) by releasing the ⁄4-scale or ⁄2-scale cone
assembly from the penetrometer and allowing the cone to drop freely into the grease for 5 s 6 0.1 s.
5. Significance and Use
5.1 These test methods are applicable to greases of National Lubricating Grease Institute (NLGI) consistency numbers 0 to 4 and
are intended for use only where the size of the sample prevents the use of Test Methods D217.
5.2 Actual reduced-scale penetration values are not used or reported. They are converted to full-scale penetration values (see
Sections 9 and 10). This test method is not intended to replace the full-scale penetration as described in Test Methods D217.
Precision is better in the full-scale penetration method.
5.3 Worked penetration results, after conversion to full-scale values, may be used to establish the consistency of lubricating
greases within the above NLGI consistency numbers. The results obtained from these test methods are widely used for specification
purposes, however, no correlation with field performance has been established.
5.4 Unworked reduced-scale penetration results provide a means of evaluating the effect of storage conditions on grease
consistency.
6. Apparatus
6.1 Reduced-Scale Penetrometer—An instrument similar to that shown in Fig. 1 of Test Methods D217, adapted for use with the
1 1
⁄4-scale or ⁄2-scale cone.
NOTE 1—Any slight binding in the instrument may produce a significant error in penetration values. Periodic check of the release mechanism, cone
dimensions, and weights of cone and its movable attachments is recommended.
6.2 ⁄4-Scale Cone and Shaft, as specified in A1.1.
6.3 ⁄4-Scale Grease Worker, as specified in A1.2.
6.4 ⁄2-Scale Cone and Shaft, as specified in A1.3.
6.5 ⁄2-Scale Grease Worker, as specified in A1.4.
6.6 Temperature Bath, capable of controlling the bath temperature at 25 °C 6 0.5 °C (77 °F 6 1 °F) and designed to bring the
assembled grease worker to test temperature conveniently. Examples of suitable temperature baths include a water bath, air bath,
constant temperature test room, or a temperature-controlled metal block. If a water bath is to be used for samples for unworked,
reduced-scale penetration, means should be provided for protecting the grease surface from water and for maintaining the air above
the sample at test temperature. An air bath is preferred for bringing block greases to test temperature, but a tightly sealed container
placed in a water bath will suffice.
6.7 Spatula, corrosion-resistant, having a stiff blade approximately 13 mm (0.5 in.) wide and convenient in length.
7. Procedure for Unworked, Reduced-Scale Penetration
7.1 Sample—Sufficient sample to overfill the cup of the grease worker is required. Three measurements can be obtained from one
filling of the grease cup, by replacement of grease lost to the cone and repairing of the grease surface.
7.2 Preparing Sample for Measurement—Place the empty grease worker cup and an appropriate amount of the sample in a
container in the temperature bath maintained at 25 °C 6 0.5 °C (77 °F 6 1 °F) for sufficient time to bring the temperature of the
sample and the worker cup to 25 °C 6 0.5 °C (77 °F 6 1 °F). Transfer the sample, preferably in one lump, to overfill the cup of
D1403 − 20b
the grease worker. Make this transfer in such a manner that the grease will be worked as little as possible. Jar the cup to drive out
trapped air and pack the grease with the spatula, with as little manipulation as possible to fill the cup without air pockets. Scrape
off the excess grease extending above the rim, creating a flat surface, by moving the blade of the spatula, held inclined toward the
direction of motion at an angle of approximately 45°, across the rim of the cup, retaining the portion removed. Do not perform
any further leveling or smoothing of the surface throughout the determination of unworked, reduced-scale penetration and
determine the measurement immediately.
NOTE 2—The jarring should be as vigorous as required to remove the entrapped air without splashing the specimen from the cup. In performing these
operations, a minimum of manipulation should be used, as any agitation of the grease can have the effect of applying some working effect on the unworked
grease and affecting the result.
NOTE 3—Retain the grease removed from the cup in scraping for subsequent tests. Keep the outside of the rim of the cup clean so that the grease forced
by the penetrometer cone to overflow the cup can be returned to the cup prior to preparing the specimen for the next test.
7.3 Cleaning Cone and Shaft—Clean the penetrometer cone carefully before each test. Bending of the cone shaft can be avoided
by holding it securely in its raised position while cleaning. Do not permit grease or oil on the penetrometer shaft, as they can cause
drag on the shaft assembly. Do not rotate the cone, as this can cause wear on the release mechanism.
7.4 Reduced-Scale Penetration Measurement—Place the cup on the penetrometer table, m
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