ForewordIntroductionScopeNormative referencesTerms and definitionsSymbolsDesignation systemsNut stylesProperty classesRegular nuts (style 1) and high nuts (style 2)Thin nuts (style 0)Design of bolt and nut assembliesMaterial, heat treatment, chemical composition and steel microstructureGeneralHeat treatmentChemical compositionSteel microstructureNon-quenched and tempered nutsQuenched and tempered nutsMechanical and physical propertiesGeneralProof loadHardnessSurface integrityInspectionManufacturer's inspectionSupplier's inspectionPurchaser's inspectionDelivery of test resultsTest methodsProof load testGeneralApplicabilityApparatusTesting deviceTest procedureTest results and requirementsHardness testsGeneralApplicabilityTest methodsTest procedures for routine inspectionHardness determined in the threadHardness determined in the coreUniformity of hardness for quenched and tempered nuts (QT)Requirements for non-quenched and tempered nuts (NQT)Requirements for quenched and tempered nuts (QT)Steel microstructureGeneralApplicabilityTest methodTest results and requirementsRetempering testGeneralTest procedureTest results and requirementsSurface discontinuity inspectionMarking and labellingGeneral requirementsProperty class marking symbols for nuts with full loadabilityProperty class marking symbols for nuts with reduced loadabilityManufacturer’s identification markNut markingMarking of the packages (labelling)Thread dimensions of the test mandrel (normative)Design principles for nuts (informative)Basic design principles for nutsNuts with diameters D < 5 mm and D > 39 mmStress under proof load, S (informative)Bibliography