ISO INTERNATIONAL STANDARD 5855-1 Third edition 1999-10-15 Aerospace MJ threads - Part 1: General requirements Aéronautique et espace - Filetage MJ - Partie 1: Exigences génerales ISO Reference number ISO 5855-1:1999(E) by IHS under lic mitted without license from IHS Not for Resale ISO 5855-1:1999(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out through ISO technical liaison'with IsO, also take part in the work. sO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. International Standard ISO 5855-1 was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles Subcommittee SC 4, Aerospace fastener systems. This third edition cancels and replaces the second edition (IsO 5855-1:1988), of which it constitutes a technical revision. IsO 5855 consists of the following parts, under the general title Aerospace - MJ threads: Part 1:General requirements Part 2: Limit dimensions for bolts and nuts Part 3: Limit dimensions for fittings for fluid systems @ISO1999 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic nternational Organizationfor Standardization Casepostale56·CH-1211Geneve20·Switzerland nternet [email protected] Printed in Switzerland onal Organization for Standardizatior INTERNATIONAL STANDARD @ISO ISO 5855-1:1999(E) Aerospace MJ threads : Part 1: General requirements 1 Scope This part of IsO 5855 specifies the general requirements for MJ threads used in aerospace construction. It determines the basic triangular profile for this type of thread and gives a system for designating the diameter and pitch combinations. For all diameters 1,6 mm to 300 mm, it offers in the form of tables the basic dimensions and tolerances for a selection of diameter and pitch combinations. It also provides the method of calculation for the dimensions and tolerances for any diameter and pitch combination not given in the tables, including threads with a diameterinexcessof3oomm. For limit dimensions for bolts and nuts of nominal diameter 1,6 mm to 39 mm, see IsO 5855-2. For limit dimensions fo fittings for fluid systems, see ISsO 5855-3. 2 Normative reference The following normative document contains provisions which, through reference in this text, constitute provisions of this apply. However, parties to agreements based on this part of IsO 5855 are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. 3 Term and definition For the purpose of this part of IsO 5855, the following term and definition apply. 3.1 basicprofile theoretical profile, in an axial plane, corresponding to the basic dimensions (without tolerances) of the thread, i.e major diameter, pitch diameter and minor diameter See Figure 1. 4 Basic profile 4.1 Symbols See Figure 1. Copyright Internatio onal Organization for Standardizatior Not for Resale