ASME_B18.8.5M-1994.pdf

Fax:062084389Aug29200114:49P.01l06PINSMACHINE DOWEL PINS-HARDENED GROUND METRIC SERIESIFI NOTES:1.ASMEB18.8.5M;sastandarddevelopedthroughtheproceduresofTheAmericanSocietyofMechanicalEngineers.B1B.8.5MisunderthejurisdictionofASMEStandardsCommitteeB18andisthedirectresponsibilityofSubcommittee8.2.Publishedforthefirsttimein1994,thispresentationdoesnotincludethegovernmentpartnumberingsystemwhichis inAppendixBoftheASMEstandard.AdiscussionoftherelationshiptoISO8734:Paral-letPinsofHardenedSteelandMarlensiticSteel(DowelPins)isin-cludedin Para.1.6.Allparagraphsarenumberedidenticaf/ytothoseinthestandard.3.ASMEB18.8.5M-1994 isreprintedwithpermissionofitspublisher,TheAmericanSocietyofMechanicalEngineers,ThreeParkAvenue,NewYork,NY10016-5990,U.S.A.ASME818.8.5M19941.INTRODUCTORY NOTES1.3Dimensions1.1Scope1.1.1This standard covers the dimensionaland general data for hardened ground dowelpins in sizes 1.5-25 mm in two series recoo-nized as American National Standard,which arewidely used in general industrial applications.1.1.2The inclusion of dimensional data in thisstandard is not intended to imply that all prod-ucts described are stock production sizes.Con-sumers are requested to consult with suppliersconcerning the availability of theproduct.1.2DescriptionHardened ground dowel pins are straightpins designed to be force-fitled into a part toprovide alignment or location in the assembly.The hardness and closely controlled diameterprovide controlled fit and wear resistance for pinapplications.One end of the pin is chamferedto assist in insertion while the opposite end hasa crown profile to minimize edge damage dur-ing insertion.All dimensions in this standard are in rnil-limeters unless otherwise noted and apply be-fore plating or coating.1.4OptionsOptions,where specified,shall be at thediscretion of the supplier,unlessotherwiseagreed upon by the supplier and purchaser.1.5TerminologyFordefinitionsoftermsrelatingtofas-teners or component features thereof used inthis standard,refer to ASME 818.12,Glossaryof Terms for Mechanical Fasteners.See pageK-37.1.6ComparisonwithISO 8734The standard series outside diameterdimensions are within the dimensional limits ofISO 8734,but the ISO 8734 pins may exceedthe maximum standard pin diameter for 4 mmand larger sizes.ISO 8734 hasonlyoneseries,J-16Fax:062084389Aug29200114:50P.02/06ASMEB18.8.SM1994MACHINE DOWEL PINS-HARDENED GROUND METRIC SERIESPINSdI2.2.1EndContours.The ends of hardenedground machine dowel pins shall be reasonablyflat and perpendicular to the axis of the pin.Oneend of the pin shall be pointed and the otherend crowned tothedimensionsspecified inTable2.On the pointed end,the edge formedby the surface of point and the end of the pinmay be slightly rounded or broken.2.3.1Measurement.The length of hardenedground machine dowel pins shall be measuredoverall from end-to-end,parallel to thepinaxis.2.3.2ToleranceonLength.Thetoleranceon the length ofhardenedgroundmachinedowelpinsshallbe+0.0-0.5mmforallsizesand lengths.2.3.3PreferredLengths.The preferred sizesand lengths in which hardened ground machinedowel pins are normally available are depictedin Table 2.Other sizes and lengths are pro-duced as required by the purchaser.2.2.2PointConcentricity.Forpins havingnominal lengths equal to four times the basicpin diameter and longer,the concentricity be-tween the diameterofpoint and the pin diam-eter shall be such that the minimum length ofpoint on the pinISnot Jess than 0.3 mm(seeFig.1).2.3Length2.3.4EffectiveLength.The effective length,L,(that portion of the pin length bounded bythe length of point on one end and the radius ofcrown on the other)on short dowel pins shall2.2Ends2.1.2Roundness.Theouterperipheryofhardened ground machine dowel pins shall con-form to true round about the longitudinal axis ofthe pin within 0.0025 mm when measured withequipment that will detect a lobed surface.Lo.3min2.1.1Size.Hardened ground dowel pins aredescribed in two series,the Standard series hav-ing minimum diameters 0.003 to 0.008 mm overthe nominal diameter,intended for initial instal-lation;and the Oversize series having minimumdiameters 0.025 to 0.030 mm over the nominaldiameter,intended for replacement use.Forboth series thediametershall be ground,orgroundandlapped,totheoutside diameter di-mensions specified in Table 1.Fig.1PointConcentricity2.GENERALDATA FORDOWELPINS2.1Diameterbut this standard includes on Oversize series.The standard length increments in this standardarefewerthanthoseinISO8734.On pinlengths less than35mm only,the even lengthsmatch the ISO lengths.For lengths over 50 mmthe standardincrementin length is 10 mm,whereasISO 8734has5mm as a standard in-crement.The pin length tolerance is unilateral,at-0.5mm,but ISO 8734 has bilateral toler-ances.Thus,pins of lengths 10 mm and shortermay be shorter than the minimums in ISO 8734,but all longer pins will meet the ISO require-ments.Thestandard surface roughness re-quirernents are finer than the ISO 8734 require-ments.ISO 8734 has a spherical