ASTM_D_2370_-_16_2021.pdf

Designation:D237016(Reapproved 2021)Standard Test Method forTensile Properties of Organic Coatings1This standard is issued under the fixed designation D2370;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.Scope1.1 This test method covers the determination of theelongation,tensile strength,and stiffness(modulus of elastic-ity)of organic coatings when tested as free films.1.2 The values stated in SI units are to be regarded asstandard.The values given in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.1.3 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.1.4 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 PanelsD882 Test Method for Tensile Properties of Thin PlasticSheetingD1005 Test Method for Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD3980 Practice for Interlaboratory Testing of Paint andRelated Materials(Withdrawn 1998)3D4708 Practice for Preparation of Uniform Free Films ofOrganic Coatings3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 elongation at break,nthe increase in specimenlength from the point of initial load application to the point offilm rupture in a tension test.3.1.2 gage length,nthe initial length of the test specimenbetween the jaws of the tensile tester.3.1.3 stiffness(modulus of elasticity),nthe load per unitarea required to elongate the film 1%from the first point in thestress-strain curve where the slope becomes constant.3.1.4 stress-strain curve,nthe curve resulting from a plotof tensile load against the distance of jaw separation(elonga-tion of specimen).3.1.5 tensile strength(nominal),nthe load per originalunit area at which a specimen fails or yields in a tension(pull)test.4.Summary of Test Method4.1 Free unsupported films of the materials to be tested areprepared in accordance with Practice D4708.The tensileproperties of the free films are determined by means of a tensiletesting apparatus.5.Significance and Use5.1 Tensile properties determined by this method are ofvalue in studying the behavior of coatings subjected to envi-ronmental stresses,such as those produced by aging andweathering.(See Refs.(1-10).)45.2 Tensile properties may vary with specimen thickness,method of preparation,gage length,rate of load application,tensile tester response,and type of grips used.Consequently,where precise comparative results are desired,these factorsmust be carefully controlled.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 Nov.1,2021.Published November 2021.Originallyapproved in 1965.Last previous edition approved in 2016 as D2370 16.DOI:10.1520/D2370-16R21.2For 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 thisstandard.Copyright 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 and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1?6.Apparatus6.1 Equipment for applying films of uniform thickness asdescribed in Practices D823.6.2 Micrometer Film Thickness Gage as described in TestMethod D1005.6.3 Tensile Tester of the constant rate of jaw separation type,equipped with load cells having capacities of 1 to 50 N(0.2 to10 lb),and equipped with computer with t