SPECIFICATIONFOR
SCREWED STUDS
Part 2.Remendations forhigh grade studs
BRITISHSTANDARDSINSTITUTION
INCORPORATED BY ROYAL CHARTER
BRITISH STANDARDS HOUSE 2PARK ST LONDON W.1TELEGRAMS:STANDARDS LONDON W1 TELEPHONE:MAYFAIR9000
Ts BRIris STANDARD，having bcen approved by thccndorsed by the Chairman of the Engineering Divisional Mechanical Engineering Industry Standards Committce andCouncil was published under the authority of the GeneralCouncil on 19th August 1964.
The information in this British Standard has been extractedfrom Anurican Standard Class 5Interferencc-fit thread(ASA B1.2-1963) with the permission of the publisher TheAmerican Society of Mechanical Engineers United Engin- eering Centre 345 East 47th St. New York 17 N.Y.
The Institution desires to call attention to the fact that thisBritish Standard doesnot purport to include all the necessary provisions of a contract.
In order to keepabreast of progress in the industriesSuggestions for improvements will bc recorded and in due concernec BritishStandards are subject to periodicalreview.coursc brought tothe notice of the mittees charged withthe revision of the standards to which they refer.
A plete list of British Standards numbering over6000 fully indexed and with a notc of the contents of cach willbe found in the British Standards Yearbook which may besulted in many publiclibraries and similar institutions.
This stardard makes reference to the following BritishStandard:
B.S.1768.Unified precision hexagon bolts screws and nuts(UNC and UNF threads).Normal serics.
Britshtandardsreevisedwhenecesarybytissuetrofamendmentslipsorofrevisededitions.Itisinportantthatpossessionof thelatest amendments oreditions. usersofBritishStandardsshouldascertain thattheyarein
CONTENTS
Co-operating organizationsForeword
RECOMMENDATIONS
SECTION ONE:GENERAL
1.Scope2.Material 93.Tables 94.Extension of the standard 10 9.
SECTION TWO:RECOMMENDED CONDITIONS OP USE AND INSPECTION
5. Studs 126.Holes 127.Pitch and angle variables 8.Lubrication 129.Driving speed 1310.Reiation ofdriving torque tolengthof 13engagement 1311.Breakloose torques afterrcapplication 1312.Assembly torques for reapplication 13
TABLES
1.External dimensionsfor Class5standardthreads 142.InternaldimensionsforClass5standard threads3.Interferences cngagement Iengths and torques 15for Class5standard threads 16
CO-OPERATING.ORGANIZATIONS
The Mechanical Engincering Industry Standards Committee.consists ofrepresentatives from the following GovernnientAssociated Omces'Technical Commitee departments and scientific and industrial organizations:Association of Consulting Engincers Association ofMiningElectrical and Mechanical Engineers"BritishElectricaland Allied Manufacturers'Association British Compressed Air SocietyBritishInternal CombustionEngine Manufacturers'Association British Gear Manufacturers'AssociationBritish Mechanical EngineeringFederation*British Railways Board CrownAgentsforOversca Governments andAdministrationsD.S.I.R.National EngineeringLaboratory Electricity Council the Generating Board and the Area Boards in*Engincering EquipmentUsers'Association England andWalesHigh Commission of India Gas Council.Institute of Marine Engincers Institute ofPetroleumInstitutionof Heating andVentilating Engineers Institution ofCivil Engineers Institution of GasEngineersInstitution of Mechanical Engineers(Automobile Division） Institution of Mechanical EngineersLootive andAlliedManufacturers'Association of Great Britain Institution ofProduction Engincers*Machine Tool Trades AssociationMinistry ofDefence ArmyDeparment Ministry of Defence Navy DeparumentMinistry of Labour (H.M.Factory Inspectorate) MinistryofPowerMinistryofTransport MinistryofPublicBuilding andWorks*National Physical Laboratory (D.S.I.R.) National Coal BoardRoyal Institute of BritishArchitects RadioIndustry CouncilThe Government departments and scientifc and industrial organizations markedwith an asterisk in the above list togetherod withthefollowingwere directlyrepresentedon the mittceAgricultural Engineers'Association Association of Hydraulic Equipment ManufacturersBritish Bolt Nut.Screw and Rivet Federation BrightBolt&Nut Manufacturers Association BrightSteel Bar AssociationBritishCycle&MotorCycle IndustriesAssociationLimited British Constructional SteelworkAssociationBritishInstitute of ColdFormed andTurnedParts Manufacturers Council ofBritish Manufacturers ofPetroleum EquipmentElectronic Engineering Assoclation Heat TreatedBolt AssociationInstitute ofIron&Stecl Wire Manufacturers MinistryofAviationRolled Thread ScrewAssociation Post OfficeSociety of Motor Manufacturers and Traders Ltd. Washer Manufacturers'AssociationIndividual manufacturers
BRITISHSTANDARDSPECIFICATIONFOR
SCREWEDSTUDS
Part2.Remendationsforhighgradestuds
(with Class 5Interference fit threads to American Standard ASA B1.12)
FOREWORD
When Part1of B.S.2693was issued several years ago it was recognized that theusers.The thread tolerances specified could result in clearance or interference one gradeof stud forwhich it providedwould not mect therequirements of allfits and in the former case locking depended on therun-out threads.Some users however felt that truc interference fits were csscntialfor thcir nceds and it wasagreed topreparc afurther part of the standard giving limits and tolerances for a higher grade of stud.
This proved to be a very difficult task and in spite of exhaustive discussionsreached.Whie the subject was stillunder discussion a trialAmerican Standardyears of research and study similar to thatwhich the British Committce had for Class 5interference fit threads was published.This standard was based onproposed to undertake andit was suggested that it would be pointless toduplicate this work when the results were already available for use in the TrialAmcricanStandardASA B1.12.
It has accordingly been decided to issue this information in the form of aBritish StandardRemendation.In doing so it is emphasized that ASAB1.12 does not claim to be the last word on the subject; although the absenceCommittce responsible to confirm it without technical change，as an American ofadverse mentandreception of favourable reports have now led theStandard users in the U.S.A.are still urged to report on the results whethergood or bad of applying its requirements.Information gained from suchor revision of the standard.
These Remendations are issued on the same basis and users are moststronglyrequested to advise theBritishStandardsInstitution of theresults theyobtain. In this way it is hoped ultimately to be able to specify a series of stud
