Designation:D143−14StandardTestMethodsforSmallClearSpecimensofTimber1ThisstandardisissuedunderthefixeddesignationD143;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONTheneedtoclassifywoodspeciesbyevaluatingthephysicalandmechanicalpropertiesofsmallclearspecimenshasalwaysexisted.Becauseofthegreatvarietyofspecies,variabilityofthematerial,continuallychangingconditionsofsupply,manyfactorsaffectingtestresults,andeaseofcomparingvariables,theneedwillundoubtedlycontinuetoexist.Inthepreparationofthesemethodsfortestingsmallclearspecimens,considerationwasgivenbothtothedesirabilityofadoptingtestmethodsthatwouldyieldresultscomparabletothosealreadyavailableandtothepossibilityofembodyingsuchimprovementsasexperiencehasshowndesirable.InviewofthemanythousandsoftestsmadeunderasinglecomprehensiveplanbytheU.S.ForestService,theformerForestProductsLaboratoriesofCanada(nowFPInnovations),andothersimilarorganizations,thesetestmethodsnaturallyconformcloselytothemethodsusedbythoseinstitutions.ThesetestmethodsaretheoutgrowthofastudyofbothAmericanandEuropeanexperienceandmethods.Thegeneraladoptionofthesetestmethodswilltendtowardaworld-wideunificationofresults,permittinganinterchangeandcorrelationofdata,andestablishingthebasisforacumulativebodyoffundamentalinformationonthetimberspeciesoftheworld.Descriptionsofsomeofthestrengthtestsrefertoprimarymethodsandsecondarymethods.Primarymethodsprovideforspecimensof2by2-in.(50by50-mm)crosssection.Thissizeofspecimenhasbeenextensivelyusedfortheevaluationofvariousmechanicalandphysicalpropertiesofdifferentspeciesofwood,andalargenumberofdatabasedonthisprimarymethodhavebeenobtainedandpublished.The2by2-in.(50by50-mm)sizehastheadvantageinthatitembracesanumberofgrowthrings,islessinfluencedbyearlywoodandlatewooddifferencesthansmallersizespecimens,...
