ISO 3842:2006

INTERNATIONAL ISO
STANDARD 3842
Fourth edition
2006-12-15
Road vehicles — Fifth wheels —
Interchangeability
Véhicules routiers — Sellette d'attelage — Interchangeabilité

Reference number
©
ISO 2006
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
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
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
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2006
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2006 – All rights reserved

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 committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO 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/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. 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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 3842 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 15,
Interchangeability of components of commercial vehicles and buses.
This fourth edition cancels and replaces the third edition (ISO 3842:2001), which has been technically revised.

INTERNATIONAL STANDARD ISO 3842:2006(E)

Road vehicles — Fifth wheels — Interchangeability
1 Scope
This International Standard lays down the dimensional characteristics necessary for mounting and
interchangeability of the fifth wheel mounted on a mounting plate (standard fifth wheel, Clause 4) or directly on
the frame (direct-mounted fifth wheel, Clause 5) of towing vehicles for semi-trailers. It applies to the fifth
wheels intended to hitch on semi-trailers equipped with a:
⎯ 50 coupling pin as defined in ISO 337;
⎯ 90 coupling pin as defined in ISO 4086.
Dimensions not specified are left to the discretion of the component manufacturer.
Test conditions and strength requirements to be met by 50 and 90 fifth wheel coupling are specified in
ISO 8717.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 337, Road vehicles — 50 semi-trailer fifth wheel coupling pin — Basic and mounting/interchangeability
dimensions
ISO 1726, Road vehicles — Mechanical coupling between tractors and semi-trailers —Interchangeability
ISO 4086, Road vehicles — 90 semi-trailer fifth wheel kingpin — Interchangeability
ISO 8717, Commercial road vehicles — Fifth wheel couplings — Strength tests
3 Designation
Fifth wheels meeting the requirements of this International Standard shall be identified by the following details
in the order specified:
1) reference to this International Standard;
2) code FW 50 for 50 mm fifth wheels and FW 90 for 90 mm fifth wheels according to Clause 4;
3) or code DFW 50 for 50 mm direct-mounted fifth wheels according to Clause 5;
4) number of class of fifth wheel height H according to Tables 1 or 3;
5) class of transversal width (A or B) according to Table 2 for direct-mounted fifth wheels according to
Clause 5.
EXAMPLES
⎯ 50 mm fifth wheel coupling having a height within the range of class 1: Fifth wheel ISO 3842 FW 50-1;
⎯ 90 mm fifth wheel coupling having a height within the range of class 4: Fifth wheel ISO 3842 FW 90-4;
⎯ 50 mm direct-mounted fifth wheel coupling having a width of Class A and a height within the range of class 1:
Direct-mounted fifth wheel ISO 3842 DFW 50-1-A.
4 Standard fifth wheels
4.1 Fixing holes
The position of the fixing holes on the mounting plate shall be as shown in Figure 1. The position of the
...