1、Designation: D3363 05 (Reapproved 2011)1Standard 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 nu
2、mber 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 Department of Defense.1NOTEFigure 1 was corrected editorially in August 2011.1. Scope*1.1
3、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 state
4、d 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
5、 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 a
6、gainst 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
7、 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 d
8、etermine 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
9、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 purch
10、aser andthe seller.5. Apparatus5.1 A set of calibrated drawing leads (preferred) or equiva-lent calibrated wood pencils meeting the following scale ofhardness:6B25B24B23B22B2B2HB2F2H22H23H24H25H26HSofter Harder(1)The difference between two adjacent leads shall be consid-ered one unit of hardness.5.2
11、 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, o
12、r 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.6.2 The film thickness of the coating shall be as specified oras agreed upon between the pur
13、chaser and the seller.6.3 Conduct the test at 23 6 2C (73.5 6 3.5F) and 50 65 % relative humidity.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
14、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/D3363-05R11E01.2Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, ht
15、tp:/www.ansi.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Procedure7.1 For wood pencils, remove approximately 5 to 6 mm (316to14 in.) of wood from the point
16、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 abrasi
17、ve 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 drawingleads, see Fig. 2 as the illustration. The desired edge may beobtained by cementing
18、the abrasive paper to a flat motor-drivendisk. By supporting the pencil at 90 to the rotating disk auniform flat lead end may be obtained more reproducibly.7.2 For wood pencils, remove approximately 5 to 6 mm (316to14 in.) of wood from the point of each pencil using adraftsman-type mechanical sharpe
19、ner, 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 sectio
20、n is obtained, free of chips or nicks inthe edge of the cross section. The desired edge may be obtainedby cementing the abrasive paper to a flat motor-driven disk. Bysupporting the pencil at 90 to the rotating disk a uniform flatlead end may be obtained more reproducibly.7.3 Place the coated panel o
21、n a level, firm, horizontalsurface. Starting with the hardest lead, hold the pencil or leadholder firmly with the lead against the film at a 45 angle (pointaway from the operator) and push away from the operator.Exert sufficient uniform pressure downward and forward eitherto cut or scratch the film
22、or to crumble the edge of the lead. Itis suggested that the length of the stroke be 6.5 mm (14 in.).7.4 Repeat the process down the hardness scale until apencil is found that will not cut through the film to the substrate(either metal or a previous coat) for a distance of at least 3 mm(18 in.) (see
23、8.1.1).NOTE 1The operator must watch closely for cutting into or scratchingthe film. Some finishes contain compounds that may tend to lubricate thefilm. Checks should be made by close visual inspection and by fingernailfeel.NOTE 2In conducting the test, if the sharp edge of the lead is slightlychipp
24、ed or crumbled, the lead must be resharpened.7.5 Continue the process until a pencil is found that willneither cut through nor scratch the surface of the film. Anydefacement of the film other than a cut (gouge) is considered ascratch. Record each end point (if applicable) for gouge andscratch hardne
25、ss (see 8.1).NOTE 3With some films, the two end points will be identical.7.6 Make a minimum of two determinations for gougehardness (7.4) and scratch hardness (7.5) for each pencil orlead.8. Report8.1 Report the following information:8.1.1 The two end points as follows:8.1.1.1 Gouge HardnessThe hard
26、est pencil that will leavethe film uncut for a stroke length of at least 3 mm (18 in.).8.1.1.2 Scratch HardnessThe hardest pencil that will notrupture or scratch the film.8.1.2 The make and grade of lead or pencil used, and8.1.3 Any deviation from standard conditions, includingroughness in the finis
27、h.9. Precision and Bias9.1 PrecisionIn an interlaboratory test of this test methodwith three different films on panels, ten laboratories andoperators, and repeated by switching leads and panels betweenlaboratories, the within-laboratory standard deviation wasfound to be 0.52 and the between-laborato
28、ry standard deviationwas found to be 0.61. Based on these standard deviations, thefollowing criteria should be used for judging the acceptabilityof results at a 95 % confidence level:9.1.1 RepeatabilityTwo results obtained by two operatorswithin a laboratory using the same pencils and panels should
29、beconsidered suspect if they differ by more than one pencil uniton the scale described in 5.1.9.1.2 ReproducibilityTwo results, each the mean of atleast two determinations, obtained by operators in differentlaboratories using the same pencils and panels or differentpencils with the same panels shoul
30、d be considered suspect ifthey differ by more than one pencil unit on the scale describedin 5.1.9.1.3 BiasSince there is no acceptable material suitablefor determining the bias for the procedure in this test methodfor measuring pencil hardness, bias cannot be determined.10. Keywords10.1 hardness (sc
31、ratch); pencil hardnessFIG. 1 View of Wood Pencil after SharpeningFIG. 2 View of Mechanical Holder with Sharpened Drawing LeadD3363 05 (2011)12SUMMARY OF CHANGESCommittee D01 has identified the location of selected changes to this standard since the last issue(D3363 00) that may impact the use of th
32、is standard.(1) Figs. 1 and 2 were added to make it clearer to the user ofthis standard how the trimmed wood from wood pencil andgeometry of the lead tip should appear.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin t
33、his standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must
34、be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of there
35、sponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700,
36、West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D3363 05 (2011)13
