ASTM_D_2134_-_19.pdf

Designation:D213419Standard Test Method forDetermining the Hardness of Organic Coatings with aSward-Type Hardness Rocker1This standard is issued under the fixed designation D2134;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.1.Scope*1.1 This test method covers the determination of the relativedegree of surface hardness of organic coatings using a specificapparatus used in the coatings industry.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 This test method does not purport to address all of thesafety problems,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.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:2D823 Practices for Producing Films of Uniform Thicknessof Paint,Coatings and Related Products on Test PanelsD1005 Test Method for Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD1186 Test Methods for Nondestructive Measurement ofDry Film Thickness of Nonmagnetic Coatings Applied toa Ferrous Base(Withdrawn 2006)3D1400 Test Method for Nondestructive Measurement of DryFilm Thickness of Nonconductive Coatings Applied to aNonferrous Metal Base(Withdrawn 2006)3D3924 Specification for Standard Environment for Condi-tioning and Testing Paint,Varnish,Lacquer,and RelatedMaterialsD4138 Practices for Measurement of Dry Film Thickness ofProtective Coating Systems by Destructive,Cross-Sectioning MeansE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Significance and Use3.1 Sward-type hardness rocker instruments have been usedby the coatings industry for more than a half a century as anondestructive test instrument to measure cure and ultimatesurface hardness of organic coatings(see Refs.(1)through(2).4This test method is useful within laboratories to quicklyscreen and measure the surface hardness of candidate coatings.NOTE1In previous task group work designed to establish an ASTMmethod for measuring hardness of organic coatings with Sward-typehardness rocker instruments,round-robin test results continually showedpoor interlaboratory reproducibility.This lack of interlaboratory agree-ment could have resulted from dimensional variations among instruments,with the contact rocker rings as the most likely offender in that regard.There are several producers of Sward-type hardness rockers makinginstruments that differ among themselves in net weight and ring radius.Some of them exceed the measurements and net weight called for in thistest method.4.Apparatus4.1 Hardness TesterThe hardness tester shall consist oftwo flat,chromium-plated bronze rings with uniformly roundoutside edges.These rings are separated and held in positionwith a weighted lower member and three horizontal light-weight spacer bars with the topmost one supporting a weightadjustable in height.A rack across the center section supportstwo bubble tube-type levels that are used to measure theamplitude of the oscillations of the hardness tester.The rate ofchange in amplitude is used as a measure of hardness or1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.23 on Physical Properties of Applied Paint Films.Current edition approved Dec.1,2019.Published January 2020.Originallyapproved in 1962.Last previous edition approved in 2012 as D2134 93(2012).DOI:10.1520/D2134-19.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.4Boldface numbers in parentheses refer to the list of references at the end of thistest method.*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 fo