ASTM_D_3363_-_22.pdf

Designation:D336322Standard Test Method forFilm Hardness by Pencil Test1This standard is issued under the fixed designation D3363;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 a procedure for rapid,inexpen-sive determination of the film hardness of an organic coatingon a metal or similarly hard substrate in terms of drawing leadsor pencil leads of known hardness.1.2 This test method is similar in content(but not techni-cally equivalent)to ISO 15184.NOTE1Other procedures are available to measure permanent defor-mation of organic coatings under the action of a single point(stylus tip)including but not limited to Test Methods D2197,D5178,and G171.1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.4 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.1.5 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:2D2197 Test Method for Adhesion of Organic Coatings byScrape AdhesionD5178 Test Method for Mar Resistance of Organic CoatingsG171 Test Method for Scratch Hardness of Materials Usinga Diamond Stylus2.2 Other Standards:ISO 15184 Determination of film hardness by pencil test33.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 gouge hardness,nthe hardest pencil lead that willleave the film uncut for a stroke length of at least 3 mm(18in.);also referred to as pencil hardness.3.1.2 scratch hardness,nthe hardest pencil lead that willnot rupture or scratch the film.4.Summary of Test Method4.1 A coated panel is placed on a firm horizontal surface.The pencil is held firmly against the film at a 45 angle(pointaway from the operator)and pushed away from the operator fora minimum of 6.5 mm(14-in.)stroke.The process is startedwith the hardest pencil and continued down the scale ofhardness to either of two end points:one,the pencil that willnot cut into or gouge the film(pencil hardness),or two,thepencil that will not scratch the film(scratch hardness).NOTE2A result in which the film coating is removed,revealing thesubstrate or previous coating layer if two or more coatings are present isconsidered a cut or gouge.A result in which the lead leaves a blemish ordefacement of the film coating,but does not reveal the substrate isconsidered a scratch.A result in which the lead is transferred to the filmcoating,but does not result in any damage is a pencil mark.See Fig.1 andFig.2.5.Significance and Use5.1 Pencil hardness measurements have been used by thecoatings industry for many years to determine the hardness ofclear and pigmented organic coating films.This test methodhas also been used to determine the cure of these coatings,especially when using forced dried heat.5.2 This test method is convenient in developmental workand in production control testing in a single laboratory.Itshould be recognized that the results obtained may varybetween different laboratories when different manufacturerspencils as well as when different substrates are used.To1This 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 June 1,2022.Published July 2022.Originally approvedin 1974.Last previous edition approved in 2020 as D3363 20.DOI:10.1520/D3363-22.2For 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 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