ASTM_D_1474_-_D_1474M_-_13.pdf

Designation:D1474/D1474M13Standard Test Methods forIndentation Hardness of Organic Coatings1This standard is issued under the fixed designation D1474/D1474M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript 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 These test methods cover the determination of theindentation hardness of organic materials such as dried paint,varnish,and lacquer coatings,when applied to an acceptableplane rigid surface,for example,metal or glass.1.2 Two methods are covered as follows:SectionsMethod AKnoop Indentation Hardness6 12Method BPfund Indentation Hardness13 191.3 Method A,which has the greater precision,provideshardness values in terms of Knoop Hardness Number(KHN).Method B provides hardness in terms of Pfund HardnessNumber(PHN).Although the hardness value scales of thesemethods differ,the methods agree in the ranking of coatinghardness.1.4 Test MethodAof these test methods is similar in content(but not technically equivalent)to ISO 6441-1and ISO 6441-2.1.5 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.6 This standard does not purport to address the safetyconcerns,if any,associated with its use.It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D823 Practices for Producing Films of Uniform Thicknessof Paint,Varnish,and Related Products on Test PanelsD1005 Test Method for Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD7091 Practice for Nondestructive Measurement of DryFilm Thickness of Nonmagnetic Coatings Applied toFerrous Metals and Nonmagnetic,Nonconductive Coat-ings Applied to Non-Ferrous MetalsE384 Test Method for Knoop and Vickers Hardness ofMaterials2.2 Other Standards:ISO 6441-1 Paints and VarnishesDetermination of micro-indentation hardnessPart 1:Knoop hardness by mea-surement of the indentation length3ISO 6441-2 Paints and VarnishesDetermination of micro-indentation hardnessPart 2:Knoop hardness by mea-surement of the indentation depth under load33.Terminology3.1 Definitions:3.1.1 indentation hardness,nthe resistance to penetrationby an indenter.3.1.2 Knoop indenter,na pyramidal diamond of pre-scribed dimensions.3.1.3 Pfund indenter,nhemispherical quartz or sapphireindenter of prescribed dimensions.3.1.4 Knoop hardness number,KHN,nthe indentationhardness determined with a Knoop indenter,and calculated asfollows:KHN5 L/Ap5 L/l2Cp(1)where:L=load applied to the indenter,kg,l=measured length of long diagonal of the indentation,mm,Cp=indenter constant relating l2to Ap,andAp=projected area of indentation,mm2.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings,Materials,and Applications and are the directresponsibility of Subcommittee D01.23 on Physical Properties of Applied PaintFilms.Current edition approved Nov.1,2013.Published December 2013.Originallyapproved in 1957.Last previous edition approved in 2008 as D1474 98(2008).DOI:10.1520/D1474_D1474M-13.2For 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 American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.*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 3.1.5 Pfund hardness number,PHN,nthe indentationhardness determined with a Pfund indenter,and calculated asfollows:PHN5 L/A 5 4L/d25 1.27L/d2!(2)where:L=load/kg applied to the indenter,kg,A=area of projected indentation,mm2,andd=diameter of projected indentation,mm.4.Significance and Use4.1 Indentation hardness measurements have proven to beuseful in rating coatings on rigid substrates for their resistanceto mechanical abuse,such as that produced by blows,gouging,and scratching.These measurements do not necessarily char-acterize the resistance to mechanical abuse of coatings that arerequired to remain intact when deformed.5.Test Specimens5.1 The substrate for the coating shall be an acceptableplane rigid surface such as glass or metal.5.2 The coating thickness on any one panel shall be uniformwithin 3 m 0.1 mil.Coatings to be compa