BS ISO BRITISH STANDARD 13921:2008 Aerospace Screws, 100 degrees reduced countersunk head. internal offset cruciform ribbed or unribbed drive. normal shank. short or medium length MJ threads. metallic material, coated or uncoated, strength classes less than or equal to 1 10o MPa - Dimensions ICS 49.030.20 BSi NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW British Standards BS ISO13921:2008 National foreword This British Standard is the UK implementation of ISO13921:2008. It supersedes BSA311:1997 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee ACE/12, Aerospace fasteners and fastening systems. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard Amendments/corrigendaissuedsincepublication was published under the authority ofthe Standards Policy and Strategy Date Comments Committee on 31 October 2008 BSI 2008 ISBN9780 580550270 BS ISO 13921:2008 ISO INTERNATIONAL STANDARD 13921 Second edition 2008-08-15 Aerospace Screws, 1o0 degrees reduced countersunk head, internal offset cruciform ribbed or unribbed drive, normal shank, short or medium length MJ threads, metallic material, coated or uncoated,strengthclasseslessthanor equal to 1 100 MPa Dimensions Aeronautique et espace-Vis a tete fraisee 100 degrés reduite a empreintecruciforme deportee,avec ou sans saillies antiderapantes, a tige normale etfiletages MJ courts ou delongueurmoyenne, en materiau metallique, revetues ounon revetues, des classes de resistanceinferieuresouégalesa1100MPa-Dimensions Referencenumber ISO 13921:2008(E) @ISO2008 BS ISO 13921:2008 ISO13921:2008(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHTPROTECTEDDOCUMENT ? ISO2008 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means. ISO's member body in the country of the requester. ISO copyright office Casepostale56.CH-1211Geneva20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland ii @ISO2008-All rights reserved BS ISO 13921:2008 ISO13921:2008(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies InternationalElectrotechnicalCommission(lEC)onallmattersofelectrotechnicalstandardization International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2 adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. ISO13921waspreparedbyTechnicalCommitteeISO/TC20,Aircraftandspacevehicles,Subcommittee Sc 4,Aerospacefastenersystems. This second edition cancels and replaces the first edition (isO 13921:1996), which has been technically revised. ISO 2008 - All rights reserved ili BS ISO 13921:2008 BS ISO 13921:2008 ISO 13921:2008(E) INTERNATIONALSTANDARD Aerospace Screws, 1oo degrees reduced countersunk head, internal offset cruciform ribbed or unribbed drive, normal shank, short or mediumlengthMJ threads,