PiecesSet: ProfessionalSuperSolidheavyDutyIndustrialHandTapsForAutomotiveAndMachinery Taper:8To10ThreadsChamferedForEasyThreadStartingInRoughSurface. Plug:3To5ThreadsChamferedGeneralUseWhenTappingToBottmOfHolesInNotCritical. Bottoming:1/2"ThreadsChamferedUseAfterThreadsHaveBeenStartedForTappingToBottomOfHose. ItsUseIsToCutYarnInMostMaterialsIncludingSteel,SomeStainlessSteel,CastIronAndNon-FerrousMaterialsSuchAsAluminum,BrassAndManyMore. DesignedForYourConvenience. HighGrade,HighQualityProductSKC. HeavyDutyTypeForIndustrialUsageOfHandTaps. StrongAndQualityTypeOfHandTaps. Durable,Long-LastingUseAndEasyToUse. 100%GuaranteeNew. MadeInJapan.