Aerospace — MJ Threads — General Requirements

INTERNATIONALSTANDARDISO5855-1Third edition1999-10-15Aerospace — MJ threads —Part 1:General requirementsAéronautique et espace — Filetage MJ —This is a free 6 page sample. Access the full version online.Partie 1: Exigences généralesAReference numberISO 5855-1:1999(E)

ISO 5855-1:1999(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISOmember bodies). The work of preparing International Standards is normally carried out through ISO technicalcommittees. Each member body interested in a subject for which a technical committee has been established hasthe right to be represented on that committee. International organizations, governmental and non-governmental, inliaison with ISO, also take part in the work. ISO collaborates closely with the International ElectrotechnicalCommission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.Draft International Standards 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.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 technicalrevision.This is a free 6 page sample. Access the full version online.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 ISO 1999All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronicor mechanical, including photocopying and microfilm, without permission in writing from the publisher.International Organization for StandardizationCase postale 56 CH-1211 Genève 20 SwitzerlandInternetiso@iso.chPrinted in Switzerlandii

INTERNATIONAL STANDARD ISOISO 5855-1:1999(E)Aerospace — MJ threads —Part 1:General requirements1 ScopeThis 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 andpitch combinations. For all diameters 1,6 mm to 300 mm, it offers in the form of tables the basic dimensions andtolerances for a selection of diameter and pitch combinations. It also provides the method of calculation for thedimensions and tolerances for any diameter and pitch combination not given in the tables, including threads with adiameter in excess of 300 mm.For limit dimensions for bolts and nuts of nominal diameter 1,6 mm to 39 mm, see ISO 5855-2. For limit dimensions forfittings for fluid systems, see ISO 5855-3.2 Normative referenceThe following normative document contains provisions which, through reference in this text, constitute provisions of thispart of ISO 5855. For dated references, subsequent amendments to, or revisions of, any of these publications do notapply. However, parties to agreements based on this part of ISO 5855 are encouraged to investigate the possibility ofapplying the most recent edition of the normative document indicated below. For undated references, the latest editionof the normative document referred to applies. Members of ISO and IEC maintain registers of currently validInternational Standards.This is a free 6 page sample. Access the full version online.ISO 965-1:1998, ISO general-purpose metric screw threads — Tolerances — Part 1: Principles and basic data.3 Term and definitionFor the purpose of this part of ISO 5855, the following term and definition apply.3.1basic profiletheoretical profile, in an axial plane, corresponding to the basic dimensions (without tolerances) of the thread, i.e.major diameter, pitch diameter and minor diameterSee Figure 1.4 Basic profile4.1 SymbolsSee Figure 1.1

ISO 5855-1:1999(E) 4.2 DimensionsSee Figure 1 and Table 1.Basic deviations shall be applied to the basic dimensions.whereDis the basic major diameter of internal threadD2is the basic pitch diameter of internal threadD1is the basic minor diameter of internal threaddis the basic major diameter of external threadd2is the basic pitch diameter of external threadd1is the basic minor diameter of external threadHis the height of fundamental trianglePis the pitcha Axis of threadThis is a free 6 page sample. Access the full version online.Figure 1 — Basic profile2ISO

This is a free 6 page sample. Access the full version online. ISOISO 5855-1:1999(E)Table 1 — Dimensions3

ISO 5855-1:1999(E) ISO5 Position and form of limit profiles5.1 External threadsThe actual thread profile is located between the limit profiles shown in Figures 2 and 3.Within these limits, any continuous, non-reversing curve is permitted, provided that it comprises radii no less than0,150 11P.aPitch PbBasic and maximum profilescBasic profiledMinimum profileThis is a free 6 page sample. Access the full version online.Figure 2 — Limit profiles for external threads (clearance may be nil)4

This is a free 6 page sample. Access the full version online.ISO 5855-1:1999 Aerospace - MJ threads - Part 1: GeneralrequirementsThe remainder of this documentis available for purchase online atwww.saiglobal.com/shopSAI Global also carries a wide range of publications from a wide variety of Standards Publishers:Click on the logos to search the database online.

2 4.2 Dimensions See Figure 1 and Table 1. Basic deviations shall be applied to the basic dimensions. where D is the basic major diameter of internal thread D2 is the basic pitch diameter of internal thread D1 is the basic minor diameter of internal thread d is the basic major diameter