ASTM_D_4541_-_22.pdf

Designation:D454122Standard Test Method forPull-Off Strength of Coatings Using Portable AdhesionTesters1This standard is issued under the fixed designation D4541;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.1.Scope*1.1 This test method covers a procedure for evaluating thepull-off strength(commonly referred to as adhesion)of acoating system from metal substrates.Pull-off strength ofcoatings from concrete is described in Test Method D7234.This test offers two test protocols.Protocol 1(test to fracture)determines the greatest perpendicular force(in tension)that asurface area can bear before a plug of material is detached.Protocol 2(pass/fail)determines if the coated surface remainsintact at a defined load criteria.Fracture will occur along theweakest plane within the system comprised of the test fixture,glue,coating system,and substrate,and will be exposed by thefracture surface.This test method maximizes tensile stress ascompared to the shear stress applied by other methods,such asscratch or knife adhesion,and results may not be comparable.NOTE1The procedure in this standard was developed for metalsubstrates,but may be appropriate for other rigid substrates such as plasticand wood.Factors such as loading rate and flexibility of the substrate mustbe addressed by the user/specifier.NOTE2The procedure in this standard was developed for use on flatsurfaces.The results could have greater variability with lower values andaverages for surfaces other than flat.1.2 Pull-off strength measurements depend upon material,instrumentation and test parameters.Results obtained by eachtest method may give different results.Results should only beassessed for each test method and not be compared with otherinstruments.There are five instrument types,identified as TestMethods B-F.It is imperative to identify the test method usedwhen reporting results.NOTE3Method A,which appeared in previous versions of thisstandard,has been eliminated as its main use is for testing on concretesubstrates(see Test Method D7234).1.3 This test method describes a class of apparatus known asportable pull-off adhesion testers.2They are capable of apply-ing a concentric load and counter load to a single surface sothat coatings can be tested even though only one side isaccessible.Measurements are limited by the strength of adhe-sive bonds between the loading fixture and the specimensurface or the cohesive strengths of the glue,coating layers,and substrate.1.4 This test can be destructive and spot repairs may benecessary.1.5 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system are not necessarily exact equivalents;therefore,toensure conformance with the standard,each system shall beused independently of the other,and values from the twosystems shall not be combined.1.6 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.1.7 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:3D2651 Guide for Preparation of Metal Surfaces forAdhesiveBondingD3933 Guide for Preparation of Aluminum Surfaces forStructural Adhesives Bonding(Phosphoric Acid Anodiz-ing)D7234 Test Method for Pull-Off Adhesion Strength of Coat-ings on Concrete Using Portable Pull-Off Adhesion Tes-tersE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.46 on Industrial Protective Coatings.Current edition approved July 1,2022.Published July 2022.Originally approvedin 1993.Last previous edition approved in 2017 as D4541 17.DOI:10.1520/D4541-22.2The term adhesion tester may be somewhat of a misnomer,but its adoption bytwo manufacturers and at least two patents indicates continued usage.3For 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C