Designation: D522/D522M − 17Standard Test Methods forMandrel Bend Test of Attached Organic Coatings 1This standard is issued under the f i xed designation D522/D522M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript 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 These test methods cover the determination of theresistance to cracking (f l exibility) of attached organic coatingson substrates of sheet metal or rubber-type materials.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the 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, Varnish, and Related Products on Test PanelsD1005 Test Method for Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD2370 Test Method for Tensile Properties of Organic Coat-ingsD7091 Practice for Nondestructive Measurement of DryFilm Thickness of Nonmagnetic Coatings Applied toFerrous Metals and Nonmagnetic, Nonconductive Coat-ings Applied to Non-Ferrous Metals3. Summary of Test Method3.1 The coating materials under test are applied at uniformthickness to panels of sheet metal or rubber-type materials.After drying or curing the coated panels are bent over amandrel and the resistance to cracking of the coating isdetermined. In Test Method A the coated panels are bent overa conical mandrel. In Test Method B the coated panels are bentover cylindrical mandrels of various diameters.4. Signif i cance and Use4.1 Coatings attached to substrates are elongated when thesubstrates are dimensionally unstable, or are bent during themanufacture of articles or when the articles are abused inservice. These test methods have been useful in rating attachedcoatings for their ability to resist cracking when elongated.They have been useful in evaluating the f l exibility of coatingson f l exible substrates. The elongation of coating f i lms may alsobe tested using Test Method D2370. The correlation betweenelongation determined in accordance with Test Methods D522/D522M and D2370 is unknown.5. Test Specimen5.1 Substrates:5.1.1 If the purpose of the test is to determine the percent ofelongation of the coating material, the substrate shall becold-rolled steel strip 0.8 mm [ 1 ⁄ 32 in.] (22 gage) thick.5.1.2 If the purpose of the test is to rate the coated materialfor resistance to cracking, the substrate may be any type ofsheet metal or rubber-type material (for example, steel,aluminum, tinplate, or synthetic rubber). The thickness of thesheet metal may be less than 0.8 mm [ 1 ⁄ 32 in.] and the thicknessof the rubber-type materials may be as great as 13 mm [ 1 ⁄ 2 in.].5.1.3 The recommended panel size is 100 mm [4 in.] inwidth and 150 mm [6 in.] in length. The maximum size that theconical mandrel can accommodate is 115 mm [4 1 ⁄ 2 in.] wideand 190 mm [7 1 ⁄ 2 in.] long.5.1.4 The surface preparation of the substrate shall beagreed upon between the purchaser and the seller. Prior to the1 These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, Materials, and Applications and are the directresponsibility of Subcommittee D01.23 on Physical Properties of Applied PaintFilms.Current edition approved July 1, 2017. Published September 2017. Originallyapproved in 1939. Last previous edition approved in 2013 as D522 – 13. DOI:10.1520/D0522_D0522M-17.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service@astm.org. For Annual Book of ASTMStandards volume information, refer to the standard’s Document Summary page onthe ASTM website.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 Copyright by ASTM Int'l (all rights reserved); Fri Oct 6 11:25:35 EDT 2017Downloaded/printed byUniversity of Edinburgh (University of Edinburgh) pursuant to License Agreement. No further reproductions authorized.
