Designation: D 2783 – 03 An American National …

1 Designation: D 2783 03An American National StandardStandard Test Method forMeasurement of Extreme-Pressure Properties of LubricatingFluids (Four-Ball Method)1 This standard is issued under the fixed designation D 2783; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or This test method covers the determination of the load-carrying properties of lubricating fluids. The following twodeterminations are Load-wear index (formerly Mean-Hertz load).

2 Weld point by means of the four-ball extreme-pressure(EP) For the determination of the load-carrying properties oflubricating greases, see Test Method D standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to The values stated in either inch-pound units or SI unitsare to be regarded separately as standard. Within the text, theSI units are shown in values stated in each systemare not exact equivalents; therefore, each system shall be usedindependently of the other.

3 Combining values from the twosystems may result in nonconformance with the Referenced standards :D 2596 Test Method for Measurement of Extreme-PressureProperties of Lubricating Grease (Four-Ball Method) Standard:B Metal Balls33. line a line of plot on logarithmicpaper, as shown in Fig. 1, where the coordinates are scardiameter in millimetres and applied load in kilograms-force (ornewtons), obtained under dynamic Coordinates for the compensation lineare found in Table 1, Columns 1 and Some lubricants give coordinateswhich are above the compensation line. Known examples ofsuch fluids are methyl phenyl silicone, chlorinated methylphenyl silicone, silphenylene, phenyl ether, and some mixturesof petroleum oil and chlorinated scar diameter the average diameter, inmillimetres, of the wear scar on the stationary balls caused bythe rotating ball under an applied load in the presence of alubricant, but without causing either seizure or The wear scar obtained shall be within5 % of the values noted in Table 1, Column load the load in kilograms-force (or new-tons)

4 For each run obtained by multiplying the applied load bythe ratio of the Hertz scar diameter to the measured scardiameter at that line a line of plot on logarithmic paper, asshown in Fig. 1, where the coordinates are scar diameter inmillimetres and applied load in kilograms-force (or newtons),obtained under static scar diameter the average diameter, in milli-metres, of an indentation caused by the deformation of the ballsunder static load (prior to test). It may be calculated from theequation1 This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of on Industrial edition approved Aug.

5 10, 2003. Published September 2003. Originallyapproved in 1969. Last previous edition approved in 1998 as D 2783 88 (1998).This method was prepared under the joint sponsorship of the American Societyof Lubrication Engineers. Accepted by ASLE January Book of ASTM standards ,Vol from American National standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY Compensation Point of last nonseizure Region of incipient Region of immediate Weld 1 Schematic Plot of Scar Diameter Versus Applied Load1 Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United ~P!1/3(1)where:Dh= Hertz diameter of the contact area, andP= the static applied seizure region that region of the scar-loadcurve characterized by seizure or welding at the startup or bylarge wear scars.

6 Initial deflection of indicating pen on theoptional friction-measuring device is larger than with nonsei-zure loads. See Fig. seizure or initial seizure region that regionat which, with an applied load, there is a momentary break-down of the lubricating film. This breakdown is noted by asudden increase in the measured scar diameter and a momen-tary deflection of the indicating pen of the optional friction-measuring device. See Fig. nonseizure load the last load at which themeasured scar diameter is not more than 5 % above thecompensation line at the load. See Fig. index(or the load-carrying property of alubricant) an index of the ability of a lubricant to minimizewear at applied loads.

7 Under the conditions of this test, specificloadings in kilograms-force (or newtons) having intervals ofapproximately logarithmic units, are applied to the threestationary balls for ten runs prior to welding. The load-wearindex is the average of the sum of the corrected loadsdetermined for the ten applied loads immediately preceding theweld point under the conditions of this test, thelowest applied load in kilograms at which the rotating ballwelds to the three stationary balls, indicating the extreme-pressure level of the lubricants-force (or newtons) has Some lubricants do not allow truewelding, and extreme scoring of the three stationary ballsresults.

8 In such cases, the applied load which produces amaximum scar diameter of 4 mm is reported as the weld Summary of Test The tester is operated with one steel ball under loadrotating against three steel balls held stationary in the form ofa cradle. Test lubricant covers the lower three balls. Therotating speed is 1760640 rpm. The machine and testlubricant are brought to 18 to 35 C (65 to 95 F) and then aseries of tests of 10-s duration are made at increasing loadsuntil welding occurs. Ten tests are made below the weldingpoint. If ten loads have not been run when welding occurs andthe scars at loads below seizure are within 5 % of thecompensation line (AB Fig.)

9 1) no further runs are total can be brought to ten by assuming that loads belowthe last nonseizure load will produce wear scars equal to the compensation scar diameter. Values of these assumed scarsare given in Table 1. For clarification of last nonseizure load and weld point see Fig. Significance and This test method, used for specification purposes, dif-ferentiates between lubricating fluids having low, medium, andhigh level of extreme-pressure properties. The user of thismethod should determine to his own satisfaction whetherresults of this test procedure correlate with field performance orother bench test Extreme-Pressure Tester,5illustrated in and It is important to distinguish between the four-ball EP testerand the four-ball wear tester.

10 The four-ball EP tester is designed for testingunder more severe conditions and lacks the sensitivity necessary for thefour-ball wear , equipped with a calibrated measuring scaleand readable to an accuracy of , graduated in tenths of a Optional equipment with four-ball apparatus consists of afriction-measuring device electrically driven and conveniently graduatedin 10-s Solvent, safe, non-film forming, nonchlori-nated. (Warning Flammable. Harmful if inhaled. See )NOTE3 Certainpetroleum distillates, formerly used as solvents, havebeen eliminated due to possible toxic effects. Each user should select asolvent that can meet applicable safety requirements and thoroughly cleanmachine parts.