ASTM_D_349_-_13.pdf

Designation:D34913Standard Test Methods forLaminated Round Rods Used for Electrical Insulation1This standard is issued under the fixed designation D349;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 These test methods cover the procedures for testing rigidround rods used in electrical insulation.These round rodsinclude many types made from fibrous sheets of basicmaterials,such as cellulose,glass,or nylon in the form ofpaper,woven fabrics,or mats,bonded together by natural orsynthetic resins,or by adhesives.Such round rods includevulcanized fiber and thermosetting laminates as well as roundrods made from cast,molded,or extruded natural or syntheticresins,with or without fillers or reinforcing materials.1.2 The procedures appear in the following sections:SectionCompressive strength(axial)20 25Density28 30Dielectric strength31 39Flexural strength13 19Tensile strength7 12Water absorption26-271.3 The values stated in inch-pound units are to be regardedas the standard.1.4 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 and health practices and determine the applica-bility of regulatory limitations prior to use.For a specificwarning statement see 36.2.2.Referenced Documents2.1 ASTM Standards:2D149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD570 Test Method for Water Absorption of PlasticsD668 Test Methods of Measuring Dimensions of Rigid Rodsand Tubes Used for Electrical InsulationD792 Test Methods for Density and Specific Gravity(Rela-tive Density)of Plastics by DisplacementD1711 Terminology Relating to Electrical InsulationD6054 Practice for Conditioning Electrical Insulating Mate-rials for Testing(Withdrawn 2012)33.Terminology3.1 DefinitionsUse Terminology D1711 for definitions ofterms used in these test methods and associated with electricalor electronic insulation materials.4.Selection of Test Specimens4.1 Specimens for tests shall be selected from portions ofmaterial that are free of obvious defects unless the purpose ofthe test is to evaluate the effect of these defects.5.Conditioning5.1 In order to eliminate the effects of previous history ofhumidity exposure and to obtain reproducible results(Note 1),in all cases of dispute give the test specimens of laminated rodsa conditioning treatment for physical test as follows:5.1.1 Tensile,Flexural,and Compressive Strengths,andDensityPrior to test,condition the machined specimens inaccordance with Procedure B of Practice D6054.All specimensshall be tested at room temperature maintained at 23 6 5 C.NOTE1The following are potential reasons to undertake conditioningof specimens:(a)for the purpose of bringing the material into equilibriumwith normal or average room conditions of 23 C and 50%relativehumidity;(b)simply to obtain reproducible results,irrespective ofprevious history of exposure;or(c)to subject the material to abnormalconditions of temperature or humidity in order to predict its servicebehavior.The conditions given here to obtain reproducible results will givephysical values which could be somewhat higher or somewhat lower thanvalues under equilibrium at normal conditions,depending upon theparticular material and test.To ensure substantial equilibrium undernormal conditions of humidity and temperature,however,will requirefrom 20 to 100 days or more depending upon thickness and type ofmaterial and its previous history.Consequently,conditioning for repro-ducibility must of necessity be used for general purchase specificationsand product control tests.1These test methods are under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and are the direct responsibility ofSubcommittee D09.07 on Flexible and Rigid Insulating Materials.Current edition approved Nov.1,2013.Published November 2013.Originallyapproved in 1932.Last previous edition approved in 2007 as D349 07.DOI:10.1520/D0349-13.2For 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Dimensional Measurements6.1 Make dimensional measurements of rods in accordancewith Test Methods D668.TENSILE STRENGTH7.Significance and Use7.1 This test method is designed to