ASTM_D_3363_-_05_2011e2.pdf

Designation:D336305(Reapproved 2011)2Standard 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.1NOTEFigure 1 was corrected editorially in August 2011.2NOTEFigure 2 and Section 7 were corrected editorially in March 2012.1.Scope*1.1 This test method covers a procedure for rapid,inexpen-sive determination of the film hardness of an organic coatingon a substrate in terms of drawing leads or pencil leads ofknown hardness.1.2 This test method is similar in content(but not techni-cally equivalent)to ISO 15184.1.3 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 Other Standards:ISO 15184 Determination of film hardness by pencil test.23.Summary of Test Method3.1 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 ina 6.5-mm(14-in.)stroke.The process is started with the hardestpencil and continued down the scale of hardness to either oftwo end points:one,the pencil that will not cut into or gougethe film(pencil hardness),or two,the pencil that will notscratch the film(scratch hardness).4.Significance and Use4.1 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 forced dried using heat.4.2 This test method is especially useful in developmentalwork and in production control testing in a single laboratory.Itshould be recognized that the results obtained may varybetween different laboratories when different pencils as well aspanels are used.Every effort should be made to standardize thehardness of the lead used and the technique followed.4.3 If this test method is used as a basis for purchaseagreement,maximum precision will be achieved if a given setof referee pencils be agreed upon between the purchaser andthe seller.5.Apparatus5.1 A set of calibrated drawing leads(preferred)or equiva-lent calibrated wood pencils meeting the following scale ofhardness:6B25B24B23B22B2B2HB2F2H22H23H24H25H26HSofterHarder(1)The difference between two adjacent leads shall be consid-ered one unit of hardness.5.2 Mechanical Lead Holder,for drawing leads if used.5.3 Mechanical Sharpener,draftsman-type,is helpful fortrimming wood pencils if used.5.4 Abrasive Paper,grit No.400.6.Test Specimens and Conditions6.1 Apply the surface coating by appropriate means to asmooth rigid substrate and cure properly,or use representativepanels cut from coated stock.The panels used,the curingconditions,and the age of the coating prior to the test shall bewithin the limits agreed upon between the purchaser and theseller.1This 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 1,2011.Published June 2011.Originallyapproved in 1974.Last previous edition approved in 2005 as D3363 05.DOI:10.1520/D3363-05R11E02.2Available 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 6.2 The film thickness of the coating shall be as specified oras agreed upon between the purchaser and the seller.6.3 Conduct the test at 23 6 2C(73.5 6 3.5F)and 50 65%relative humidity.7.Procedure7.1 For wood pencils,remove approximately 5 to 6 mm(316to14in.)of wood from the point of each pencil using adraftsman-type mechanical sharpener,being careful to leave anundisturbed,unmarked,smooth cylinder of lead.Holding thepencil holder(when using drawing leads)at an angle of 90 tothe abrasive paper,rub the lead against the paper maintainingan exact angle of 90 to the abrasive paper until a flat,smoothand circular cross section is obtained,free of chips or nicks inthe edge of the cross section.For wood pencils,see Fig.1 foran illustration.For mechanical pencil holders with drawingle