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This 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.Designation: E10 17American Association State Highwayand Transportation Officials StandardAASHTO No.: T70–86Standard Test Method forBrinell Hardness of Metallic Materials1This standard is issued under the fixed designation E10; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon ( ) 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.mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.1. Scope*1.1 This test method covers the determination of the Brinellhardness of metallic materials by the Brinell indentationhardness principle. This standard provides the requirements fora Brinell testing machine and the procedures for performingBrinell hardness tests.2. Referenced Documents2.1 ASTM Standards:2E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE74 Practice of Calibration of Force-Measuring Instrumentsfor Verifying the Force Indication of Testing MachinesE140 Hardness Conversion Tables for Metals RelationshipAmong Brinell Hardness, Vickers Hardness, RockwellHardness, Superficial Hardness, Knoop Hardness, Scleroscope Hardness, and Leeb HardnessE384 Test Method for Microindentation Hardness of Materials2.2 American Bearings Manufacturer Association Standard:ABMA 10-1989 Metal Balls32.3 ISO Standards:ISO/IEC 17011 Conformity Assessment—General Requirements for Accreditation Bodies Accrediting ConformityAssessment Bodies4ISO/IEC 17025 General Requirements for the Competenceof Calibration and Testing41.2 This standard includes additional requirements in fourannexes:Verification of Brinell Hardness Testing MachinesBrinell Hardness Standardizing MachinesStandardization of Brinell Hardness IndentersStandardization of Brinell Hardness Test BlocksAnnex A1Annex A2Annex A3Annex A41.3 This standard includes nonmandatory information in anappendix which relates to the Brinell hardness test:Table of Brinell Hardness NumbersExamples of Procedures for DeterminingBrinell Hardness UncertaintyAppendix X1Appendix X21.4 At the time the Brinell hardness test was developed, theforce levels were specified in units of kilograms-force (kgf).Although this standard specifies the unit of force in theInternational System of Units (SI) as the Newton (N), becauseof the historical precedent and continued common usage of kgfunits, force values in kgf units are provided for information andmuch of the discussion in this standard refers to forces in kgfunits.1.5 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 appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.1.6 This 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 Recom-3. Terminology and Equations3.1 Definitions:3.1.1 calibration—determination of the values of the significant parameters by comparison with values indicated by areference instrument or by a set of reference standards.3.1.2 verification—checking or testing to assure conformance with the specification.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service@astm.org. For Annual Book of ASTMStandards volume information, refer to the standard’s Document Summary page onthe ASTM website.3Available from American Bearing Manufacturers Association (ABMA), 2025M Street, NW, Suite 800, Washington, DC 20036, http://www.americanbearings.org.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http://www.ansi.org.1This test method is under the jurisdiction of ASTM Committee E28 onMechanical Testing and is the direct responsibility of Subcommittee E28.06 onIndentation Hardness Testing.Current edition approved April 1, 2017. Published May 2017. Originallyapproved in 1924. Last previous edition approved in 2015 as E10 – 15a. DOI:10.1520/E0010-17.*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 States1

E10 173.2 Equations:3.2.1 The Brinell hardness number is calculated as:3.1.3 standardization—to bring in conformance with aknown standard through verification or calibration.3.1.4 Brinell hardness test—an indentation hardness testusing a verified machine to force an indenter (tungsten carbideball with diameter D), under specified conditions, into thesurface of the material under test. The diameter of the resultingindentation d is measured after removal of the force.3.1.5 Brinell hardness number—a number, which is proportional to the quotient obtained by dividing the test force by thecurved surface area of the indentation which is assumed to bespherical and of the diameter of the ball.3.1.6 Brinell hardness scale—a designation that identifiesthe specific combination of ball diameter and applied forceused to perform the Brinell hardness test.3.1.7 Brinell hardness testing machine—a Brinell hardnessmachine used for general testing purposes.3.1.8 Brinell hardness standardizing machine—a Brinellhardness machine used for the standardization of Brinellhardness test blocks. The standardizing machine differs from aregular Brinell hardness testing machine by having tightertolerances on certain parameters.3.1.9 force-diameter ratio—a number calculated as the ratioof the test force in kgf to the square of the indenter balldiameter in mm (see Table 1).HBW 52F kgf πD D 2 D 2 2 d 2!(1)where:Fkgf test force in kgf,D diameter of the indenter ball in mm, andd measured mean diameter of the indentation in mm(see Table 1).3.2.2 The average mean diameter d̄ of a set of n indentationsis calculated as:d̄ 5d 1 1d 2 1 1d nn(2)where:d1, d2, . dn diameter values of the indentations in mm,andn number of indentations (see Annex A4).3.2.3 The repeatability R in the performance of a Brinellhardness machine at each hardness level, under the particularverification conditions, is estimated by the percent range ofdiameter values of n indentations made on a standardized testblock as part of a performance verification, relative to theaverage of the n measured diameter values d̄ (Eq 2), defined as:TABLE 1 Symbols and DesignationsSymbolDesignationDDiameter of the ball, mmFTest force, NFkgfR 5 100 313Fgnwhere gn is the acceleration due to gravity.gn 9.80665 N/kgfdd s 1 d 1d s 2 d 1{1d s N dNH̄ 5where d(1), d(2) . d(N) are the measured indentationdiameters in mm, and N is the number of diameter measurements (typically 2).hForceDiameterratioHBWD 2 œD 2 2 d 225F kgfD2E 5 100 3Brinell hardness(4)S?DH̄ 2 H STDH STD(5)where:H̄ (Eq 4) average of n hardness tests H1, H2, ., Hn madeon a standardized test block as part of a performance verification, certified average hardness value of the standardHSTDized test block, andTest Force5Surface area of indentation5H 1 1H 2 1 1H nn3.2.5 The error E in the performance of a Brinell hardnessmachine at each hardness level, under the particular verification conditions, is estimated by the percent error of the averageof n indentation measurements made on a standardized testblock as part of a performance verification relative to thecertified average hardness value of the standardized test block,defined as:Depth of the indentation, mmh5(3)3.2.4 The average H̄ of a set of n Brinell hardness measurementvalues H1, H2, ., Hn is calculated as:Diameter value of the indentation, mmd5d̄where:dmax diameter value of the largest measured indentationdmin diameter value of the smallest measured indentation,andd̄ (Eq average of the diameter values of the n indentations.2)Test force, kgfF kgf 5d max 2 d min2F kgfπ D s D 2 œD 2 2 d 2 d2