ASTM_D_953_-_10.pdf

Designation:D95310Standard Test Method forBearing Strength of Plastics1This standard is issued under the fixed designation D953;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.Scope*1.1 This test method covers the determination of the bearingstrength of rigid plastics in either sheet form,molded form,orin thermoset pultruded form.Procedure A is applicable fortension loading and Procedure B for compression loading.1.2 Test data obtained by this test method is relevant andappropriate for use in engineering design.1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.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.NOTE1There is no known ISO equivalent to this standard.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical Testing3.Terminology3.1 DefinitionsFor definitions of technical terms pertain-ing to plastics used in this test method,see Terminology D883.3.2 Definitions of Terms Specific to This Standard:3.2.1 bearing areathe diameter of the hole multiplied bythe thickness of the specimen.3.2.2 bearing strengththe bearing stress at which thebearing hole is deformed 4%of its diameter.3.2.3 bearing stressthe applied load in newtons(orpounds-force)divided by the bearing area in mm2(or in2).3.2.4 edge distance ratiothe distance from the center ofthe bearing hole to the edge of the specimen in the direction ofthe principal stress,divided by the diameter of the hole.3.2.5 maximum bearing stressthe maximum load in new-tons(or pounds-force)sustained by the specimen,divided bythe bearing area.4.Significance and Use4.1 This bearing strength test for plastics is intended toapply in the specification of various thermoplastic or thermo-setting products in sheet form where rivets,bolts,or similarfastenings are to be used in joining members or sections.It alsois intended to apply wherever sheet materials of the classesindicated are required to sustain edgewise loads that areapplied by means of pins or rods of circular cross section whichpierce the sheet perpendicular to the surface.4.2 The purpose of the test is to determine the bearingstrength of the material and to show the bearing stress versusthe deformation of the hole.The allowable deformation of thehole in the material should be such as to produce no loosenessof joints.4.3 While it is a known fact that higher strength materialswill generally give higher bearing strengths,there is nosatisfactory method by which bearing strength may be esti-mated from tensile or compressive properties of the material.4.4 Before proceeding with this test method,referenceshould be made to the specification of the material being tested.Any test specimen preparation,conditioning,dimensions ortesting parameters or combination thereof covered in therelevant ASTM materials specification shall take precedenceover those in this test method.If there are no relevant ASTMmaterial specifications then the default conditions apply.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.Current edition approved April 1,2010.Published June 2010.Originallyapproved in 1948.Last previous edition approved in 2009 as D953-09.DOI:10.1520/D0953-10.2For 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.3Attention is also directed to Terminology E6.*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 5.Apparatus5.1 Testing MachineA properly calibrated universal test-ing machine that can be operated at a speed of 1.3 6 0.3 mm(0.05 6 0.01 in.)/min,except that in cases of certain types ofmaterial it may be necessary to operate at a slower speed.Thepercentage of error of the testing machine shall be no morethan 61%of the applied load as determined in accordancewith Practices E4.5.2 Tension Loading FixtureA three-plate fixture of hard-ened steel simi