ASTM_D_4366_-_16_2021.pdf

Designation:D436616(Reapproved 2021)Standard Test Methods forHardness of Organic Coatings by Pendulum Damping Tests1This standard is issued under the fixed designation D4366;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.Scope1.1 These test methods cover the use of pendulum dampingtesters in the determination of hardness of organic coatings thathave been applied to acceptably plane rigid surfaces,such as ametal or glass panel.1.2 Two test methods based on different pendulum types arecovered as follows:1.2.1 Test Method AKnig Pendulum Hardness Test.1.2.2 Test Method BPersoz Pendulum Hardness Test.1.3 This standard is similar in content(but not technicallyequivalent)to ISO 1522.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 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.1.6 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 PanelsD1005 Test Method for Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD3891 Practice for Preparation of Glass Panels for TestingPaint,Varnish,Lacquer,and Related ProductsD7091 Practice for Nondestructive Measurement of DryFilm Thickness of Nonmagnetic Coatings Applied toFerrous Metals and Nonmagnetic,Nonconductive Coat-ings Applied to Non-Ferrous Metals2.2 Other Standard:3ISO 1522 Paints and Varnishes Pendulum Damping Test3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 Knig hardness,ntime in seconds for the swingamplitude of the Knig pendulum to decrease from 6 to 3.3.1.2 Persoz hardness,ntime in seconds for the swingamplitude of the Persoz pendulum to decrease from 12 to 4.4.Summary of Test Methods4.1 A pendulum resting on a coating surface is set intooscillation(rocking)and the time for the oscillation amplitudeto decrease by a specified amount measured.The damping timeis influenced by a combination of physical properties,amongsthardness,elasticity,coefficient of friction and shore of thesample under test.The damping time decreases with thedecrease of hardness or an increase of elasticity or coefficientof friction.5.Significance and Use5.1 The pendulum damping test has been found to havegood sensitivity in detecting differences in coating hardness,where hardness is defined as resistance to deformation.5.2 The two procedures given in these test methods embodythe principle that the amplitude of oscillation of a pendulumtouching a surface decreases more rapidly the softer thesurface.However,these test methods differ in respect topendulum dimensions,and period and amplitude of oscillation.5.3 In general,the damping time of the Knig pendulum isapproximately half that of the Persoz pendulum.5.4 The Persoz pendulum has a greater degree of discrimi-nation than the Knig for measuring the hardness of soft1This 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 1,2021.Published June 2021.Originallyapproved in 1984.Last previous edition approved in 2016 as D4366 16.DOI:10.1520/D4366-16R21.2For 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.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.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.1coatings,but it may not be as suitable for testing hard,slipperyfilms because of its tendency to skid on surfaces with a lowcoefficient of frict