ASTM D2783-03(2009)e1

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
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Designation: D2783 − 03(Reapproved 2009)
Standard Test Method for
Measurement of Extreme-Pressure Properties of Lubricating
Fluids (Four-Ball Method)
This standard is issued under the fixed designation D2783; 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.
ε NOTE—Subsection 3.1.9 was editorially corrected in April 2014.
1. Scope 3.1.1 compensation line—a line of plot on logarithmic
paper, as shown in Fig. 1, where the coordinates are scar
1.1 This test method covers the determination of the load-
diameter in millimetres and applied load in kilograms-force (or
carrying properties of lubricating fluids. The following two
newtons), obtained under dynamic conditions.
determinations are made:
3.1.1.1 Discussion—Coordinates for the compensation line
1.1.1 Load-wear index (formerly Mean-Hertz load).
are found in Table 1, Columns 1 and 3.
1.1.2 Weldpointbymeansofthefour-ballextreme-pressure
3.1.1.2 Discussion—Some lubricants give coordinates
(EP) tester.
which are above the compensation line. Known examples of
1.2 For the determination of the load-carrying properties of
such fluids are methyl phenyl silicone, chlorinated methyl
lubricating greases, see Test Method D2596.
phenyl silicone, silphenylene, phenyl ether, and some mixtures
1.3 This standard does not purport to address all of the
of petroleum oil and chlorinated paraffins.
safety concerns, if any, associated with its use. It is the
3.1.2 compensation scar diameter—the average diameter, in
responsibility of the user of this standard to establish appro-
millimetres, of the wear scar on the stationary balls caused by
priate safety and health practices and determine the applica-
the rotating ball under an applied load in the presence of a
bility of regulatory limitations prior to use.
lubricant, but without causing either seizure or welding.
1.4 The values stated in SI units are to be regarded as the
3.1.2.1 Discussion—The wear scar obtained shall be within
standard. The values given in parentheses are for information
5 % of the values noted in Table 1, Column 3.
only.
3.1.3 corrected load—the load in kilograms-force (or new-
2. Referenced Documents
tons) for each run obtained by multiplying the applied load by
2.1 ASTM Standards:
the ratio of the Hertz scar diameter to the measured scar
D2596 Test Method for Measurement of Extreme-Pressure
diameter at that load.
Properties of Lubricating Grease (Four-Ball Method)
3.1.4 Hertz line—a line of plot on logarithmic paper, as
2.2 ANSI Standard:
shown in Fig. 1, where the coordinates are scar diameter in
B 3.12 Metal Balls
millimetres and applied load in kilograms-force (or newtons),
obtained under static conditions.
3. Terminology
3.1.5 Hertz scar diameter—the average diameter, in
3.1 Definitions:
millimetres, of an indentation caused by the deformation of the
balls under static load (prior to test). It may be calculated from
This test method is under the jurisdiction of ASTM Committee D02 on
the equation
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.L0.11 on Tribiological Properties of Industrial Fluids and
22 1/3
D 5 8.73 310 P (1)
~ !
h
Lubricates.
Current edition approved April 15, 2009. Published July 2009. Originally
where:
approved in 1969. Last previous edition approved in 2003 as D2783 – 03.
D = Hertz diameter of the contact area, and
This method was prepared under the joint sponsorship of the American Society
h
of Lubrication Engineers. Accepted by ASLE January 1969. DOI: 10.1520/D2783-
P = the static applied load.
03R09E01.
3.1.6 immediate seizure region—that region of the scar-load
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
curve characterized by seizure or welding at the startup or by
Standards volume information, refer to the standard’s Document Summary page on
large wear scars. Initial deflection of indicating pen on the
the ASTM website.
3 optional friction-measuring device is larger than with nonsei-
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036. zure loads. See Fig. 1.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D2783 − 03 (2009)
index is the average of the sum of the corrected loads
determinedforthetenappliedloadsimmediatelyprecedingthe
weld point.
3.1.10 weld point—under the conditions of this test, the
lowest applied load in kilograms at which the rotating ball
welds to the three stationary balls, indicating the extreme-
pressure level of the lubricants-force (or newtons) has been
exceeded.
3.1.10.1 Discussion—Some lubricants do not allow true
welding, and extreme scoring of the three stationary balls
results. In such cases, the applied load which produces a
maximum scar diameter of 4 mm is reported as the weld point.
ABE—Compensation line.
B—Point of last nonseizure load.
4. Summary of Test Method
BC—Region of incipient seizure.
CD—Region of immediate seizure.
4.1 The tester is operated with one steel ball under load
D—Weld point.
rotating against three steel balls held stationary in the form of
FIG. 1 Schematic Plot of Scar Diameter Versus Applied Load
a cradle. Test lubricant covers the lower three balls. The
rotating speed is 1760 6 40 rpm. The machine and test
TABLE 1 Suggested Form for Recording Test Results
lubricant are brought to 18 to 35°C (65 to 95°F) and then a
Column 2 Column 3 Column 5
Column 1
series of tests of 10-s duration are made at increasing loads
Column4
Applied Average Scar Compensation Corrected
LD until welding occurs. Ten tests are made below the welding
h
A
Diameter, Scar Diameter, Load,
Load, kg
Factor
A
(L) point. If ten loads have not been run when welding occurs and
mm (X) mm kg (LD /X)
h
the scars at loads below seizure are within 5 % of the
6 0.95
8 1.40
compensation line (AB Fig. 1) no further runs are necessary.
10 0.21 1.88
The total can be brought to ten by assuming that loads below
13 0.23 2.67
16 0.25 3.52 the last nonseizure load will produce wear scars equal to the
20 0.27 4.74
“compensationscardiameter.”Valuesofthese“assumed”scars
24 0.28 6.05
are given in Table 1. For clarification of “last nonseizure load”
32 0.31 8.87
and “weld point” see Fig. 1.
40 0.33 11.96
50 0.36 16.10
63 0.39 21.86
5. Significance and Use
80 0.42 30.08
100 0.46 40.5
5.1 This test method, used for specification purposes, dif-
126 0.50 55.2
ferentiates between lubricating fluids having low, medium, and
160 0.54 75.8
high level of extreme-pressure properties. The user of this
200 0.59 102.2
250 137.5
method should determine to his own satisfaction whether
315 187.1
resultsofthistestprocedurecorrelatewithfieldperformanceor
400 258
other bench test machines.
500 347
620 462
800 649
6. Apparatus
A
To convert from kilograms-force to newtons, multiply by 9.806. 5
6.1 Four-Ball Extreme-Pressure Tester, illustrated in Figs.
2 and 3.
NOTE 1—It is important to distinguish between the four-ball EP tester
3.1.7 incipient seizure or initial seizure region—that region
andthefour-ballweartester.Thefour-ballEPtesterisdesignedfortesting
at which, with an applied load, there is a momentary break-
under more severe conditions and lacks the sensitivity necessary for the
down of the lubricating film. This breakdown is noted by a
four-ball wear test.
sudden increase in the measured scar diameter and a momen-
6.2 Microscope, equipped with a calibrated measuring scale
tary deflection of the indicating pen of the optional friction-
and readable to an accuracy of 0.01 mm.
measuring device. See Fig. 1.
6.3 Timer, graduated in tenths of a second.
3.1.8 last nonseizure load—the last load at which the
measured scar diameter is not more than 5 % above the
NOTE 2—Optional equipment with four-ball apparatus consists of a
friction-measuring device electrically driven and conveniently graduated
compensation line at the load. See Fig. 1.
in 10-s markings.
3.1.9 load-wear index (or the load-carrying property of a
lubricant), n—an index of the ability of a lubricant to minimize
wear at applied loads.
Further details applicable to this method may be found in: Sayles, F. S., et al.,
“The Four-Ball E. P. Tester, An ASTM Method of Test,” National Lubricating
3.1.9.1 Discussion—Under the conditions of this test, spe-
Grease Institute, NLGIA, Vol 32, No. 5, August 1968, pp. 162–167.
cific loadings in kilograms-force (or Newtons) having intervals
SatisfactorysourcesofsupplyforthisinstrumentareFalexCorp.,1020Airpark
of approximately 0.1 logarithmic units, are applied to the three
Dr., Sugar Grove, IL 60554–9585 and Stanhope-Seta Ltd., Park Close, Egham,
stationary balls for ten runs prior to welding. The load-wear Englefield Green, Surrey, England TW20 OXD.
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D2783 − 03 (2009)
FIG. 2 Sectional View of Four-Ball Tester
FIG. 3 Four-Ball EP Test Machine
machine parts. Reagent Grade Stoddard solvent is an example of a solvent
7. Materials
that has been found suitable.
7.1 Cleaning Solvent, safe, non-film forming, nonchlori-
7.2 Rinse Solvent, same as in 7.1, but with higher volatility.
nated. (Warning— Flammable. Harmful if inhaled. See A1.1.)
ASTM n-Heptane is an example of one such rinse solvent that
NOTE 3—Certain petroleum distillates, formerly used as solvents, have
has been found suitable. (Warning—Flammable. Harmful if
been eliminated due to possible toxic effects. Each user should select a
inhaled. See A1.2.)
solvent that can meet applicable safety requirements and thoroughly clean
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D2783 − 03 (2009)
NOTE 8—The time for the apparatus to “coast” to a stop is not
7.3 Test Balls —Test balls shall be chrome alloy steel, made
considered.
from AISI standard steel No. E-52100, with diameter of 12.7
mm (0.5 in.), Grade 25 EP (Extra Polish). Such balls are 9.7 Remove the test-lubricant cup assembly; remove the
described in B3.12, for Metal Balls. The Extra-Polish finish is chuck and discard the ball.
not described in that specification. The Rockwell C hardness
9.8 Measure the scar diameter of test balls as follows:
shall be 64 to 66, a closer limit than is found in the ANSI
9.8.1 Option A—Remove the test balls. Clean the balls with
requirement.
cleaning solvent (see 7.1) and then rinse solvent (see 7.2).
Wipe dry with a soft cloth. Place the individual balls on a
8. Preparation of Apparatus
suitable holder and by means of a microscope, measure to the
nearest 0.01 mm the scar diameters both parallel (horizontal)
8.1 Thoroughly clean four new test balls, test-lubricant cup,
and chuck assemblies by first washing with cleaning solvent and normal (vertical) to the striations in the scar surface of one
of the three test balls (Note 9).
(see 7.1) and then rinse solvent (see 7.2).
9.8.2 Option B—Leave the balls clamped in the cup. Pour
NOTE 4—Do not use solvents such as carbon tetrachloride or other
out the lubricating fluid. Wash the ball surfaces with cleaning
solvents that may inherently possess load-carrying properties which may
solvent (see 7.1) and then the rinse solvent (see 7.2). Using a
affect the results.
microscope,measuretothenearest0.01mmthescardiameters
8.2 Lower the crosshead by raising the lever arm. Lock the
both parallel (horizontal) and normal (vertical) to the striations
lever arm in the raised position by means of a locking
in the scar surface of one of the three test balls (Note 9).
arrangement for that purpose.
9.8.3 Measurements by microscope of the scar diameters on
all three balls, rather than one ball as outlined in Options A or
9. Procedure
B, may be made if the operator so desires.
9.1 Place the three test balls in the test-lubricant cup. Place
NOTE9—ItisrecommendedthatpriortoselectionofOptionAorB,the
the lock ring over the test balls and screw down the nut
operator examines visually the test balls to ascertain no gross discrepancy
securely (Note 5). Pour the lubricating fluid to be tested over
in the wear scars formed on the test balls; if discrepancy is noted, then
the three test balls until they are covered.
wear scar measurements on all three test balls must be made.
NOTE 5—Subsequent independent investigations reported in 1971 by 9.9 Record (Table 1, Column 2) for the 784 N (80-kg) load
several laboratories indicate that optimum test repeatability is obtained
the average scar diameter by any one of the three techniques
when the force on the lock-down nut is maintained within the range 68 6
described in 9.8. Compare this average scar diameter with the
7 η· m (50 6 5 ft·lb), applied, and measured by means of a torque wrench.
compensation scar diameter (Table 1, Column 3).
Significantly lower weld points were obtained when the force applied was
approximately 136 N·m (100 ft·lb).
9.10 Make additional runs at consecutively higher test loads
(Table 1, Column 1), recording the measured scar diameter(s)
9.2 Bring the lubricant and cup to 18 to 35°C (65 to 95°F).
(Note 10) and discarding test balls, until welding occurs (Note
9.3 Pressoneballintotheballchuck(Note6)andmountthe
11). Make a check run at this point. If welding does not occur
chuck into the chuck-holder.
on the check run, repeat the test at the next higher load until
NOTE 6—Examine the chuck and top ball after each run. If the ball
welding is verified.
shows signs of movement in the chuck, even though welding of the
NOTE 10—Measuring the scar diameter(s) of test balls in the incipient
four-balls did not occur, the chuck should be replaced. When welding
and immediate seizure region is sometimes difficult due to the flow of
occursslippagebetweenballandchucknearlyalwaysoccurs.Ifthechuck
metal obliterating the full contact area formed by the rotating ball. In such
has metal from the top ball adhering to it, the metal must be removed or
casesthemetalflowcangenerallyberemovedorpeeledoffwithasuitable
the chuck replaced.
instrument. See Figs. 4 and 5. If the scar periphery is obscure or not well
9.4 Install the test-lubricant cup assembly on the test appa-
defined an estimate of the scar diameter is made. See Figs. 6 and 7.
ratus in contact with the fourth ball. Place the spacer between
NOTE 11—Shut off the motor immediately to prevent damage to the
tester. Excessive seizure between the ball and ball chuck may result if
cup and thrust bearing.
caution is not observed. Welding may be detected by any or all of the
9.5 Place the weight tray and sufficient weights on the
following: (1) If f
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