WORLDWIDEFASTENERSTANDARDDate:2001-01-04

WD951MECHANICALANDPERFORMANCEREQUIREMENTSOFCASEHARDENEDTHREAD

ROLLINGSCREWS

1.SCOPE.

Thisstandardspecifiestherequirementsforhighperformancecasehardenedandtemperedthread

rollingscrewsthathaveperformancecapabilitiesbeyondthosenormallyexpectedofothertypesof

tappingscrews.Itrelatestoscrewswithbasic60oscrewthreadform,metricseries,intendedfor

partsuptoandincluding5mmnominalthreaddiameteronly.Forpartsabove5mm,WD952is

recommended.

Clause3.4definesthread-formingcapabilityinsteeluptoahardnessof150HVandthicknessequal

tothescrewdiameter.Theparametersofmaterialhardnessandthreadengagementmaybevaried

byanalysisofjointrequirementsanditisthereforerecommendedthatspecificapplicationsbe

investigatedtodeterminejointcriteria.

NOTE:LubricationapprovedbyFordispermittedonpartstowhichthisspecificationisapplied

unlessotherwisespecified.

1.1REFERENCES.

ISO262-ISOgeneralpurposemetricscrewthreads-Selectedsizesfor

screws,boltsandnuts.

ISO898/2-Mechanicalpropertiesoffasteners-Part2:Nutswithspecified

proofloadvalues.

ISO5954-Coldreducedcarbonsteelsheettohardnessrequirements.

ISO6507-Metallicmaterials-Hardnesstest-Vickerstest.

WSS-M99A3-A-EmbrittlementAvoidance

2.MATERIALS.