ASTM_D_531_-_15_2019.pdf

Designation:D53115(Reapproved 2019)Standard Test Method forRubber PropertyPusey and Jones Indentation1This standard is issued under the fixed designation D531;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 the inden-tation of rubber or rubber-like materials by means of the Puseyand Jones type of plastometer.This apparatus is used tomeasure the depth of indentation of an indentor,under fixedforce into the surface of a specimen.1.2 The values stated in SI units are to be regarded as thestandard.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:2D1349 Practice for RubberStandard Conditions for Test-ingD1415 Test Method for Rubber PropertyInternationalHardnessD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesNOTE1The specific dated edition of the practice that prevails in thisdocument is referenced in the Section 9.3.Significance and Use3.1 The Pusey and Jones indentation value is the depth ofindentation,expressed in hundredths of a millimetre,of a ball3.175 mm(0.1250 in.)in diameter under an expressed force of9.8 N(2.2 lbf).This value may be used to compare theindentation resistance of rubber and rubber-like materials.3.2 The indentation value obtained should not be confusedwith hardness as measured by Test Method D1415,since in thelatter test the rubber immediately adjacent to the indentor isprecompressed.4.Apparatus4.1 Plastometer,an instrument consisting of an indentor,amass for applying the stated force on the indentor,a microm-eter for indicating the depth of the indentation,a specimenholder and support.4.1.1 Indentor,for indenting the specimen,consisting of avertical steel shaft attached,at the upper end to a depthindicator gage,and terminating in a steel sphere having adiameter of 3.175 6 0.015 mm(0.1250 6 0.0005 in.)ofpolished,noncorrosive hard metal treated to resist wear.4.1.2 Mass,the mass shall be 1000 6 0.01 g.4.1.3 Depth Indicator Gage,a micrometer attached to theplastometer,either an electronic digital gage or analog dialgage,capable of displaying indentor movement(indentation)in increments of at least 0.01 mm(0.0004 in.)and having travelof 0(zero)to no less than 3 mm(0.12 in).4.1.4 Support,a support frame,or fixture,for theplastometer,shall be configured so that the specimen holderand hence,the specimen,are perpendicular to the indentorsupport shaft and that the mass may be independently raised orlowered vertically,permitting the indentor to rest on thesurface of the specimen and the mass to be subsequentlyapplied.4.1.5 Specimen Holder,for the standard,or reference speci-men described in 5.1,shall consist of a clamping fixture of twometal plates secured by two threaded bolts.The uppermostplate shall have a hole and a slot,as depicted in Fig.1,to allowfor the unencumbered introduction of the indentor to thespecimen.1This test method is under the jurisdiction of ASTM Commitee D11 on Rubberand Rubber-like Materials and is the direct responsibility of Subcommittee D11.10on Physical Testing.Current edition approved Nov.1,2019.Published December 2019.Originallyapproved in 1939.Last previous edition approved in 2015 as D531 15.DOI:10.1520/D0531-15R19.2For 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.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 4.1.5.1 The purpose of the specimen holder is to support thespecimen in a manner that reduces,or eliminates,relativepositioning or movement that may adversely affect