Designation:D4831−00(Reapproved2010)StandardTestMethodforBuckleTearStrengthofLeather1ThisstandardisissuedunderthefixeddesignationD4831;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.1.Scope1.1Thistestmethodisintendedforuseonalltypesofleathertodeterminetheloadrequiredtotearaleatherstrapfastenedinabuckle.Thistestmethoddoesnotapplytowetblue.1.2Thevaluesstatedininch-poundunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesaremathematicalconversionstoSIunitsthatareprovidedforinformationonlyandarenotconsideredstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.SignificanceandUse2.1Thistestmethodisdesignedtomeasuretheloadrequiredtotearaleatherstrapfastenedinabuckle.Tannersandleatherbuyershavefoundthatthistestgivesanindicationoftheresistanceofleathertotearing.2.2Thistestmethodshouldbesuitableforspecificationacceptance,designpurposes,manufacturingcontrol,development,andresearch.Thethicknessofthespecimenanddirectionoftearrelativetothebackbonewillaffecttheuniformityofthetestresults.Thistestmethodmaynotapplywhentheconditionsofthetestemployeddifferwidelyfromthosespecifiedinthistestmethod.3.Apparatus3.1Gage,spring-type,formeasuringthicknessofunits,graduatedin0.5ozor0.1mmhavingaflatpressurefoot0.460.025in.(10.260.6mm)indiameterandaflatanvil0.460.025in.indiameter.Thespringshallexertaforceof1lbf(4.45N)onthefootwhenthegagereads2ozand2lbf(8.9N)whenthegagereads12oz.3.2SteelPunch,whichwillmakea3⁄16in.(4.8mm)diameterhole.3.3HarnessBuckle,1.25in.(4.7mm)witha0.17560.005-in.(4.460.1-mm)diametertongue.Itshallbe...
