ASTM_D_1478_-_20.pdf

Designation:D147820Standard Test Method forLow-Temperature Torque of Ball Bearing Grease1This standard is issued under the fixed designation D1478;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()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 determination of the extentto which a grease retards the rotation of a slow-speed ballbearing by measuring starting and running torques at lowtemperatures(below 18 C(0 F).1.1.1 Torque measurements are limited by the capacity ofthe torque-measuring equipment.1.1.2 This test method is not suitable for greases exhibitingtorque values greater than 50 000 gcm at the selected testtemperature.NOTE1When initially developed,the original dynamometer scalelimited the torque capacity to approximately 30 000 gcm;the originaldynamometer scale is obsolete,however.The suggested replacement scalehas not been evaluated;it could extend the limit to approximately50 000 gcm.1.2 The values stated in SI units are to be regarded asstandard.1.2.1 ExceptionsThe values given in parentheses are forinformation only.The exception is torque values that are givenin cgs-metric units,which are widely used in grease specifica-tions.1.3 This 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.For specific hazard and warning statements,see 6.1.1,7.2,7.4,8.7,and 8.11.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D4693 Test Method for Low-Temperature Torque of Grease-Lubricated Wheel Bearings2.2 ANSI/ABMA Standard:ABMA20:2011 Radial Bearings of Ball,Cylindrical,Roller,and Spherical Roller TypeMetric Designs(ABMACode20BCO2JO)33.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 low-temperature torque,nthe torque in gcm re-quired to restrain the outer ring of a No.6204 size open ballbearing lubricated with the test grease while the inner ring isrotated at 1 r min 6 0.05 r min at the test temperature.3.1.2 running torque,nthe 15 s average value of thetorque after rotation for a specified period of time(60 min).3.1.3 starting torque,nthe maximum torque measured atthe start of rotation.4.Summary of Test Method4.1 A No.6204 open ball bearing is packed completely fullof the test grease and cleaned off flush with the sides.Thebearing remains stationary while ambient temperature is low-ered to the test temperature and held there for 2 h.At the endof this time,the inner ring of the ball bearing is rotated at1 r min 6 0.05 r min while the restraining force on the outerring is measured.4.2 Torque is determined by multiplying the restrainingforce by the radius of the bearing housing.Both starting torqueand torque after 60 min of rotation(running torque)aredetermined.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.G0.05 on Functional Tests-Temperature.Current edition approved May 1,2020.Published June 2020.Originallyapproved in 1957.Last previous edition approved in 2018 as D1478 18.DOI:10.1520/D1478-20.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from ABMA(American Bearing Manufacturers Association),330 N.Wabash Ave.,Ste.2000,Chicago,IL 60611.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.5.Significance and Use5.1 This test method was developed using greases havingvery low torque characteristics at 54 C(65 F).Specifica-tions for greases of this type commonly require testing at thistemperature.Specifications for greases of other types canrequire testing at temperatures from 73 C to 18 C(100 F to 0 F).5.2