ASTM D217-21
(Test Method)Standard Test Methods for Cone Penetration of Lubricating Grease
Standard Test Methods for Cone Penetration of Lubricating Grease
SIGNIFICANCE AND USE
5.1 These cone penetration tests not only evaluate the consistency of lubricating greases over the full range of NLGI numbers from 000 to 6, but also evaluate the consistency of stiff greases having penetration numbers less than 85. In contrast, Test Method D937 is aimed at petrolatums and Test Method D1403 uses less precise 1/4 and 1/2-scale equipment intended for use when the sample quantity is limited.
5.2 Cone penetration test results provide one measure of the consistency of a grease. Worked penetration results are required to determine to which NLGI consistency grade a grease belongs. Undisturbed penetration results provide a means of evaluating the effect of storage conditions on grease consistency.
5.3 Although no correlation has been developed between cone penetration results and field service, the cone penetrations obtained by the four procedures are widely used for specification purposes, such as in users' material specifications and suppliers' manufacturing specifications.
SCOPE
1.1 These test methods cover four procedures for measuring the consistency of lubricating greases by the penetration of a cone of specified dimensions, mass, and finish. The penetration is measured in tenths of a millimetre.
Note 1: The National Lubricating Grease Institute (NLGI)2 classified greases according to their consistency as measured by the worked penetration. The classification system is as follows:
NLGI
Consistency Number
Worked Penetration Range,
25 °C (77 °F)
000
445 to 475
00
400 to 430
0
355 to 385
1
310 to 340
2
265 to 295
3
220 to 250
4
175 to 205
5
130 to 160
6
85 to 115
1.1.1 The procedures for unworked, worked, and prolonged worked penetration are applicable to greases having penetrations between 85 and 475, that is, to greases with consistency numbers between NLGI 6 and NLGI 000. An undisturbed penetration test, described in Appendix X1, is similar to the unworked penetration test.
1.1.2 The block penetration procedure is applicable to greases that are sufficiently hard to hold their shape. Such greases usually have penetrations below eighty-five tenths of a millimetre.
1.1.3 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.
1.2 None of the four procedures is considered suitable for the measurement of the consistency of petrolatums by penetration. Test Method D937 should be used for such products.
1.3 The dimensions of the equipment described in these test methods are given in SI units as the primary unit of measure with equivalent imperial units as accetpable alternatives where applicable. In cases where equivalent SI conversions are not known, notes are added for clarification. Temperatures and other dimensions are given in the preferred SI units; the values shown in parentheses are provided for information.
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
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D217 − 21
Designation: 50/17
Standard Test Methods for
Cone Penetration of Lubricating Grease
This standard is issued under the fixed designation D217; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* 1.2 None of the four procedures is considered suitable for
the measurement of the consistency of petrolatums by penetra-
1.1 Thesetestmethodscoverfourproceduresformeasuring
tion. Test Method D937 should be used for such products.
the consistency of lubricating greases by the penetration of a
coneofspecifieddimensions,mass,andfinish.Thepenetration 1.3 Thedimensionsoftheequipmentdescribedinthesetest
is measured in tenths of a millimetre. methods are given in SI units as the primary unit of measure
with equivalent imperial units as accetpable alternatives where
NOTE 1—The National Lubricating Grease Institute (NLGI) classified
applicable. In cases where equivalent SI conversions are not
greases according to their consistency as measured by the worked
known, notes are added for clarification. Temperatures and
penetration. The classification system is as follows:
other dimensions are given in the preferred SI units; the values
NLGI Worked Penetration Range,
Consistency Number 25 °C (77 °F)
shown in parentheses are provided for information.
000 445 to 475
1.4 This standard does not purport to address all of the
00 400 to 430
0 355 to 385
safety concerns, if any, associated with its use. It is the
1 310 to 340
responsibility of the user of this standard to establish appro-
2 265 to 295
priate safety, health, and environmental practices and deter-
3 220 to 250
4 175 to 205
mine the applicability of regulatory limitations prior to use.
5 130 to 160
1.5 This international standard was developed in accor-
6 85to115
dance with internationally recognized principles on standard-
1.1.1 The procedures for unworked, worked, and prolonged
ization established in the Decision on Principles for the
worked penetration are applicable to greases having penetra-
Development of International Standards, Guides and Recom-
tions between 85 and 475, that is, to greases with consistency
mendations issued by the World Trade Organization Technical
numbers between NLGI 6 and NLGI 000. An undisturbed
Barriers to Trade (TBT) Committee.
penetration test, described in Appendix X1, is similar to the
unworked penetration test.
2. Referenced Documents
1.1.2 The block penetration procedure is applicable to
2.1 ASTM Standards:
greases that are sufficiently hard to hold their shape. Such
D937Test Method for Cone Penetration of Petrolatum
greases usually have penetrations below eighty-five tenths of a
D1403Test Methods for Cone Penetration of Lubricating
millimetre.
Grease Using One-Quarter and One-Half Scale Cone
1.1.3 Unworked penetrations do not generally represent the
Equipment
consistency of greases in use as effectively as do worked
D4175Terminology Relating to Petroleum Products, Liquid
penetrations. The latter are usually preferred for inspecting
Fuels, and Lubricants
lubricating greases.
3. Terminology
1 3.1 Definitions:
ThesetestmethodsarethejurisdictionofASTMCommitteeD02onPetroleum
Products, Liquid Fuels, and Lubricants and are the direct responsibility of
3.1.1 consistency, n—of lubricating grease, the degree of
Subcommittee D02.G0.02 on Consistency and Related Rheological Tests. In the IP,
resistance to movement under stress.
these test methods are under the jurisdiction of the Standardization Committee.
These test methods were adopted as a joint ASTM-IP standard in 1969.
CurrenteditionapprovedJuly1,2021.PublishedJuly2021.Originallyapproved
in 1925. Last previous edition approved in 2019 as D217 – 19b. DOI: 10.1520/ For referenced ASTM standards, visit the ASTM website, www.astm.org, or
D0217-21. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
National Lubricating Grease Institute, 4635 Wyandotte St., Kansas City, MO Standards volume information, refer to the standard’s Document Summary page on
64112-1596. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D217 − 21
3.1.1.1 Discussion—Thetermconsistencyisusedsomewhat
synonymously with penetration. Generally, consistency refers
to the worked penetration of a grease.
3.1.2 lubricant, n—any material interposed between two
surfacesthatreducesthefrictionorwearbetweenthem. 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—Thedispersionofthethickenerformsa
two-phase system and immobilizes the liquid lubricant by
surfacetensionandotherphysicalforces.Otheringredientsare
commonly included to impart special properties.
3.1.4 penetration, n—of lubricating grease, the depth that
thestandardconeentersthesamplewhenreleasedtofallunder
its own weight for 5s.
3.1.5 penetrometer, n—an instrument that measures the
consistencyorhardnessofsemiliquidtosemisolidmaterialsby
measuring the depth to which a specified cone or needle under
a given force falls into the material.
3.1.6 prolonged worked penetration, n—of lubricating
grease, the penetration of a sample after it has been worked
more than 60 double strokes in a standard grease worker at a
temperature of 15°C to 30°C (59°F to 86°F).
3.1.6.1 Discussion—After the prescribed number of double
strokes, the worker and contents are brought to 25°C (77°F),
workedanadditional60doublestrokes,andpenetratedwithout
delay.
FIG. 1 Penetrometer
3.1.7 semi-solid, n—aseeminglysolidmaterialthatdeforms
under a force equal to or greater than the force of gravity and
that can be made to flow by the application of such a force so
3.2.1 block penetration, n—of lubricating grease, the pen-
long as it exceeds the yield stress of the material.
etration at 25°C (77°F) determined on the freshly prepared
faceofacubecutfromasamplethatissufficientlyhardtohold
3.1.7.1 Discussion—In the petroleum industry, lubricating
its shape.
grease, petrolatum, slack wax, and bitumen are recognized as
3.2.2 penetrometer, n—an instrument (see Fig. 1) designed
semi-solids. (Synonyms—semi-liquid and semi-fluid.)
to measure the depth to which the standard cone falls into the
3.1.8 thickener, n—in lubricating grease, a substance com-
grease.
posed of finely divided particles dispersed in a liquid lubricant
to form the product’s structure.
3.2.2.1 Discussion—In this test method, either a standard
3.1.8.1 Discussion—The thickener can be fibers (such as
penetrometer(6.2)oranoptionalpenetrometercone(A1.3)can
various metallic soaps) or plates or spheres (such as certain
be used to determine the consistency of lubricating greases.
non-soapthickeners)whichareinsolubleor,atmost,onlyvery
The penetration force is determined by the mass of the cone
slightly soluble in the liquid lubricant. The general require-
and the shaft.
mentsarethatthesolidparticlesbeextremelysmall,uniformly
4. Summary of Test Method
dispersed, and capable of forming a relatively stable, gel-like
structure with the liquid lubricant.
4.1 For unworked penetration, the sample is brought to
25°C 6 0.5°C (77°F 6 1°F) using a temperature bath. The
3.1.9 unworked penetration, n—of lubricating grease, the
sample is then transferred with as little manipulation as
penetration at 25°C (77°F) of a sample that has received only
possible into a worker cup (or other suitable container), if not
minimum disturbance in transferring to a grease worker cup or
placedtherebeforethetemperaturestabilizationstep.Thecone
dimensionally equivalent rigid container.
assembly of the penetrometer is released and allowed to drop
3.1.10 worked penetration, n—of lubricating grease, the
freely into the grease for 5s 6 0.1s. Three determinations are
penetration at 25°C (77°F), without delay, of a sample after
made and averaged to give the reported result.
60 double strokes in a standard grease worker.
4.2 For worked penetration, the sample is brought to 25°C
3.1.11 working, n—of lubricating grease,thesubjectionofa
6 0.5°C (77°F 6 1°F) and placed in the worker cup. The
sample to the shearing action of the standard grease worker.
sample is subjected to 60 double strokes in the grease worker.
3.2 Definitions of Terms Specific to This Standard: The penetration is determined immediately by releasing the
D217 − 21
coneassemblyfromthepenetrometerandallowingtheconeto 6.3.2 Grease Worker Drive, Motorized, in accordance with
drop freely into the grease for 5s 6 0.1s. Three determina- A1.6,whichallowsforworkingthegreaseatarateof60 610
tions are made and averaged to give the reported result. double strokes per minute. This apparatus is essential for the
working step of the prolonged worked penetration procedure.
4.3 For prolonged worked penetration, the sample is placed
in the worker cup and subjected to a predetermined number of 6.4 Grease Cutter, in accordance with A1.7, is used for
double strokes in the grease worker. Following completion of preparation of samples for block penetration.
the prolonged working, the grease and worker assembly are
6.5 Temperature Bath, capable of controlling the bath tem-
brought to 25°C 6 0.5°C (77°F 6 1°F) and the grease is
perature at 25°C 6 0.5°C (77°F 6 1°F) and designed to
worked an additional 60 double strokes in the grease worker.
bring the assembled grease worker to test temperature conve-
The penetration is determined immediately by releasing the
niently.Examplesofsuitabletemperaturebathsincludeawater
coneassemblyfromthepenetrometerandallowingtheconeto
bath, air bath, constant temperature test room, or a
dropfreelyintothegreasefor5s 60.1s.Threedeterminations
temperature-controlled metal block. If a water bath is to be
are made and averaged to give the reported result.
used for samples for unworked penetration, means should be
4.4 For block penetration, a cube of the grease is prepared provided for protecting the grease surface from water and for
by slicing off a thin layer using the grease cutter. The cube of maintainingtheairabovethesampleattesttemperature.Anair
grease is brought to 25°C 6 0.5°C (77°F 6 1°F) and placed bathispreferredforbringingblockgreasestotesttemperature,
on the penetrometer table with the prepared face upward. The butatightlysealedcontainerplacedinawaterbathwillsuffice.
penetration is determined by releasing the cone assembly from
6.6 Spatula, corrosion-resistant, having a stiff blade nomi-
the penetrometer and allowing the cone to drop freely into the
nally 32mm (1.25in.) wide and at least 150mm (6in.) long.
grease for 5s 6 0.1s. Three determinations are made and
6.7 Temperature-Measuring Device, with a sheath length of
averaged to give the reported result.
approximately 200mm (8in.) and a sheath diameter of ap-
5. Significance and Use
proximately 3.7mm (0.145in.) (small enough to fit through
the vent cock). The temperature range of the device should be
5.1 These cone penetration tests not only evaluate the
wide enough to allow it to be immersed in grease at approxi-
consistency of lubricating greases over the full range of NLGI
mately 38°C (100°F) without damage. The scale should have
numbers from 000 to 6, but also evaluate the consistency of
small enough divisions (or digital resolution) to allow the user
stiff greases having penetration numbers less than 85. In
to read 60.5°C (61°F).Aspacer can be applied to the upper
contrast, Test Method D937 is aimed at petrolatums and Test
1 1 portion of the sheath to hold the tip just above the perforated
Method D1403 uses less precise ⁄4 and ⁄2-scale equipment
plate of the grease worker and in the bulk of the sample (see
intended for use when the sample quantity is limited.
A1.3).
5.2 Conepenetrationtestresultsprovideonemeasureofthe
6.8 Overflow Ring (optional), in accordance with A1.8,isa
consistency of a grease. Worked penetration results are re-
useful device for catching grease scraped from the sample
quired to determine to which NLGI consistency grade a grease
surface as well as any grease forced by the penetrometer cone
belongs. Undisturbed penetration results provide a means of
to overflow from the cup. This grease can be returned to the
evaluating the effect of storage conditions on grease consis-
worker cup for subsequent testing.
tency.
5.3 Although no correlation has been developed between
7. Reagents and Materials
conepenetrationresultsandfieldservice,theconepenetrations
7.1 Appropriate Volatile Gum-free Solvent, for example,
obtained by the four procedures are widely used for specifica-
light petroleum naphtha.
tion purposes, such as in users’ material specifications and
suppliers’ manufacturing specifications. 7.2 Cloth or Paper Wiper, for wiping grease from the
penetrometer cone. The wiper should be soft, so as not to
6. Apparatus
scratch the cone.
6.1 Penetrometer, in accordance with A1.1. The instrument
8. Sampling
shallbecapableofindicatingdepthintenthsofamillimetre.A
sketch of a generic penetrometer is shown in Fig. 1.
8.1 Sample Size—Sufficient sample (at least 0.45 kg
6.2 Standard Penetrometer Cone, in accordance with A1.2, (1.1lb)) to overfill the cup of the standard grease worker is
is suitable for all penetrations.An optional penetrometer cone, required. If the sample size is insufficient and penetration
in accordance with A1.3, is suitable only for penetrations less ranges from NLGI 0 to 4, use Test Method D1403.
than 400.The optional cone should not be used to measure the 8.1.1 For block penetration, obtain a sufficient size sample
penetration of 00 and 000 grade greases. of the grease, which must be hard enough to hold its shape, to
permit cutting from it a 50mm (2in.) cube as a test specimen.
6.3 Grease Worker, comprising a grease cup, cover, and
plunger assembly, in accordance with A1.4, constructed for 8.2 Sample Preparation—Samples are prepared for the
either manual or mechanical operation. various cone penetration test methods as follows:
6.3.1 Grease Worker Drive, Manual, in accordance with 8.2.1 Unworked Penetration—Prior to performing the test,
A1.5,whichallowsforworkingthegreaseatarateof60 610 thegreasesample(ifnecessary,inasuitablecontainerorinthe
double strokes per minute. worker cup) and the test equipment (worker cup and cone)
D217 − 21
(77°F 6 1°F). This can be achieved by the use of a
temperature bath (6.5) or a combinat
...
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: D217 − 19b D217 − 21
Designation: 50/8850/17
Standard Test Methods for
Cone Penetration of Lubricating Grease
This standard is issued under the fixed designation D217; 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 four procedures for measuring the consistency of lubricating greases by the penetration of a cone
of specified dimensions, mass, and finish. The penetration is measured in tenths of a millimetre.
NOTE 1—The National Lubricating Grease Institute (NLGI) classified greases according to their consistency as measured by the worked penetration. The
classification system is as follows:
NLGI Worked Penetration Range,
Consistency Number 25 °C (77 °F)
000 445 to 475
00 400 to 430
0 355 to 385
1 310 to 340
2 265 to 295
3 220 to 250
4 175 to 205
5 130 to 160
6 85 to 115
1.1.1 The procedures for unworked, worked, and prolonged worked penetration are applicable to greases having penetrations
between 85 and 475, that is, to greases with consistency numbers between NLGI 6 and NLGI 000. An undisturbed penetration test,
described in Appendix X1, is similar to the unworked penetration test.
1.1.2 The block penetration procedure is applicable to greases that are sufficiently hard to hold their shape. Such greases usually
have penetrations below eighty-five tenths of a millimetre.
1.1.3 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.
1.2 None of the four procedures is considered suitable for the measurement of the consistency of petrolatums by penetration. Test
Method D937 should be used for such products.
These test methods are the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and are the direct responsibility of Subcommittee
D02.G0.02 on Consistency and Related Rheological Tests. In the IP, these test methods are under the jurisdiction of the Standardization Committee. These test methods were
adopted as a joint ASTM-IP standard in 1969.
Current edition approved Nov. 1, 2019July 1, 2021. Published November 2019July 2021. Originally approved in 1925. Last previous edition approved in 2019 as D217
– 19a.19b. DOI: 10.1520/D0217-19B.10.1520/D0217-21.
National Lubricating Grease Institute, 4635 Wyandotte St., Kansas City, MO 64112-1596.
*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
D217 − 21
1.3 The dimensions of the equipment described in these test methods are given in SI units as the primary unit of measure with
equivalent imperial units as accetpable alternatives where applicable. In cases where equivalent SI conversions are not known,
notes are added for clarification. Temperatures and other dimensions are given in the preferred SI units; the values shown in
parentheses are provided for information.
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:
D937 Test Method for Cone Penetration of Petrolatum
D1403 Test Methods for Cone Penetration of Lubricating Grease Using One-Quarter and One-Half Scale Cone Equipment
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
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.
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 are commonly included to impart special properties.
3.1.4 penetration, n—of lubricating grease, the depth that the standard cone enters the sample when released to fall under its own
weight for 5 s.
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.
3.1.6 prolonged worked penetration, n—of lubricating grease, the penetration of a sample after it has been worked more than 60
double strokes in a standard grease worker at a temperature of 15 °C to 30 °C (59 °F to 86 °F).
3.1.6.1 Discussion—
After the prescribed number of double strokes, the worker and contents are brought to 25 °C (77 °F), worked an additional 60
double strokes, and penetrated without delay.
3.1.7 semi-solid, n—a seemingly solid material that deforms under a force equal to or greater than the force of gravity and that
can be made to flow by the application of such a force so long as it exceeds the yield stress of the material.
3.1.7.1 Discussion—
In the petroleum industry, lubricating grease, petrolatum, slack wax, and bitumen are recognized as semi-solids. (Synonyms—
semi-liquid and semi-fluid.)
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
D217 − 21
FIG. 1 Penetrometer
3.1.8 thickener, n—in lubricating grease, a substance composed of finely divided particles dispersed in a liquid lubricant to form
the product’s structure.
3.1.8.1 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 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.
3.1.9 unworked penetration, n—of lubricating grease, the penetration at 25 °C (77 °F) of a sample that has received only minimum
disturbance in transferring to a grease worker cup or dimensionally equivalent rigid container.
3.1.10 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.
3.1.11 working, n—of lubricating grease, the subjection of a sample to the shearing action of the standard grease worker.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 block penetration, n—of lubricating grease, the penetration at 25 °C (77 °F) determined on the freshly prepared face of a
cube cut from a sample that is sufficiently hard to hold its shape.
3.2.2 penetrometer, n—an instrument (see Fig. 1) designed to measure the depth to which the standard cone falls into the grease.
3.2.2.1 Discussion—
In this test method, either a standard penetrometer (6.2) or an optional penetrometer cone (A1.3) can be used to determine the
consistency of lubricating greases. The penetration force is determined by the mass of the cone and the shaft.
D217 − 21
4. Summary of Test Method
4.1 For unworked penetration, the sample is brought to 25 °C 6 0.5 °C (77 °F 6 1 °F) using a temperature bath. The sample is
then transferred with as little manipulation as possible into a worker cup (or other suitable container), if not placed there before
the temperature stabilization step. The cone assembly of the penetrometer is released and allowed to drop freely into the grease
for 5 s 6 0.1 s. Three determinations are made and averaged to give the reported result.
4.2 For worked penetration, the sample is brought to 25 °C 6 0.5 °C (77 °F 6 1 °F) and placed in the worker cup. The sample
is subjected to 60 double strokes in the grease worker. The penetration is determined immediately by releasing the cone assembly
from the penetrometer and allowing the cone to drop freely into the grease for 5 s 6 0.1 s. Three determinations are made and
averaged to give the reported result.
4.3 For prolonged worked penetration, the sample is placed in the worker cup and subjected to a predetermined number of double
strokes in the grease worker. Following completion of the prolonged working, the grease and worker assembly are brought to 25 °C
6 0.5 °C (77 °F 6 1 °F) and the grease is worked an additional 60 double strokes in the grease worker. The penetration is
determined immediately by releasing the cone assembly from the penetrometer and allowing the cone to drop freely into the grease
for 5 s 6 0.1 s. Three determinations are made and averaged to give the reported result.
4.4 For block penetration, a cube of the grease is prepared by slicing off a thin layer using the grease cutter. The cube of grease
is brought to 25 °C 6 0.5 °C (77 °F 6 1 °F) and placed on the penetrometer table with the prepared face upward. The penetration
is determined by releasing the cone assembly from the penetrometer and allowing the cone to drop freely into the grease for 5 s
6 0.1 s. Three determinations are made and averaged to give the reported result.
5. Significance and Use
5.1 These cone penetration tests not only evaluate the consistency of lubricating greases over the full range of NLGI numbers from
000 to 6, but also evaluate the consistency of stiff greases having penetration numbers less than 85. In contrast, Test Method D937
1 1
is aimed at petrolatums and Test Method D1403 uses less precise ⁄4 and ⁄2-scale equipment intended for use when the sample
quantity is limited.
5.2 Cone penetration test results provide one measure of the consistency of a grease. Worked penetration results are required to
determine to which NLGI consistency grade a grease belongs. Undisturbed penetration results provide a means of evaluating the
effect of storage conditions on grease consistency.
5.3 Although no correlation has been developed between cone penetration results and field service, the cone penetrations obtained
by the four procedures are widely used for specification purposes, such as in users’ material specifications and suppliers’
manufacturing specifications.
6. Apparatus
6.1 Penetrometer, in accordance with A1.1. The instrument shall be capable of indicating depth in tenths of a millimetre. A sketch
of a generic penetrometer is shown in Fig. 1.
6.2 Standard Penetrometer Cone, in accordance with A1.2, is suitable for all penetrations. An optional penetrometer cone, in
accordance with A1.3, is suitable only for penetrations less than 400. The optional cone should not be used to measure the
penetration of 00 and 000 grade greases.
6.3 Grease Worker, comprising a grease cup, cover, and plunger assembly, in accordance with A1.4, constructed for either manual
or mechanical operation.
6.3.1 Grease Worker Drive, Manual, in accordance with A1.5, which allows for working the grease at a rate of 60 6 10 double
strokes per minute.
6.3.2 Grease Worker Drive, Motorized, in accordance with A1.6, which allows for working the grease at a rate of 60 6 10 double
strokes per minute. This apparatus is essential for the working step of the prolonged worked penetration procedure.
D217 − 21
6.4 Grease Cutter, in accordance with A1.7, is used for preparation of samples for block penetration.
6.5 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
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.
6.6 Spatula, corrosion-resistant, having a stiff blade nominally 32 mm (1.25 in.) wide and at least 150 mm (6 in.) long.
6.7 Temperature-Measuring Device, with a sheath length of approximately 200 mm (8 in.) and a sheath diameter of approximately
3.7 mm (0.145 in.) (small enough to fit through the vent cock). The temperature range of the device should be wide enough to allow
it to be immersed in grease at approximately 38 °C (100 °F) without damage. The scale should have small enough divisions (or
digital resolution) to allow the user to read 60.5 °C (61 °F). A spacer can be applied to the upper portion of the sheath to hold
the tip just above the perforated plate of the grease worker and in the bulk of the sample (see A1.3).
6.8 Overflow Ring (optional), in accordance with A1.8, is a useful device for catching grease scraped from the sample surface as
well as any grease forced by the penetrometer cone to overflow from the cup. This grease can be returned to the worker cup for
subsequent testing.
7. Reagents and Materials
7.1 Appropriate Volatile Gum-free Solvent, for example, light petroleum naphtha.
7.2 Cloth or Paper Wiper, for wiping grease from the penetrometer cone. The wiper should be soft, so as not to scratch the cone.
8. Sampling
8.1 Sample Size—Sufficient sample (at least 0.45 kg
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.