ISO 1161:2026

International
Standard
ISO 1161
Sixth edition
Series 1 freight containers —
2026-10
Corner and intermediate fittings —
Specifications
Conteneurs de la série 1 — Pièces de coin et pièces de fixation
intermédiaires — Spécifications
Reference number
© ISO 2026
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Dimensional requirements . 1
4.1 General .1
4.2 Detailed dimensional and manufacturing requirements .2
5 Strength requirements . 2
6 Design requirements . 3
6.1 Loading .3
6.1.1 General .3
6.1.2 Design loads .3
6.1.3 Lifting and tipping .3
6.1.4 Longitudinal restraint .3
6.1.5 Vertical restraint (compression only) .4
6.1.6 Lashing and securing .4
6.1.7 Misgather (offset loading) .4
6.2 Compulsory features .4
7 Minimum bearing area — top and bottom corner and intermediate fittings . 5
8 Corner and intermediate fitting marking . 5
9 Required prototype tests . 5
9.1 General .5
9.2 Casting defect checks.5
9.3 Tests .5
9.3.1 General .5
9.3.2 Top fitting stacking test .5
9.3.3 Top intermediate fitting stacking test .6
9.3.4 Bottom fitting stacking test .6
9.3.5 Bottom intermediate fitting stacking test .6
9.3.6 Twistlock lifting and tipping test .6
9.3.7 Cargo hook lifting test .6
9.3.8 Cargo hook lifting test 2 .6
9.3.9 Impact test .6
9.3.10 Lashing bar test .7
9.3.11 Misgather test .7
9.3.12 Longitudinal securing test .7
10 Required sample production line tests . 7
10.1 Casting defect checks.7
10.2 Tests .7
Annex A (normative) Testing methodology .13
Annex B (informative) Typical examples of twistlock lifting devices .18
Annex C (informative) Chemical composition of container corner fittings .20
Bibliography .21

iii
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
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with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 104, Freight containers, Subcommittee SC 1,
General purpose containers.
This sixth edition cancels and replaces the fifth edition (ISO 1161:2016), which has been technically revised.
The main changes are as follows:
— removed all imperial measures;
— added 4.2.1;
— revised design load values for top, bottom and intermediate fittings in 6.1.1 to 6.1.7 in accordance with
the updated Gross Mass R = 36 000 kg;
— renamed Clause 9;
— rewrote wording of 9.1 in accordance with new title of Clause 9;
— revised test values in 9.3.1 to 9.3.12 in accordance with revised design load from 6.1.1 to 6.1.7;
— rewrote drawings of top, bottom and intermediate fittings with the dimensions in Figures 2, 3 and 4;
— revised values in drawings in Annex A, “Testing methodology” according to updated values in 9.3.1
to 9.3.12.
— added a new Annex C.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
This document on corner fittings represents the collaborative efforts of technical and operational experts
from all sectors of the transportation industry. Figure 1 shows the fittings for the top and bottom corners of
series 1 freight containers, which provide compatibility in interchange between transportation modes. Care
has been taken to limit consideration only to the details of fittings which are vital to this function.
This document specifies the size and configuration of corner and intermediate fitting apertures. The faces of
the corner and intermediate fittings having apertures for the engagement of handling and securing devices
have specified thickness and tolerances as shown in Figures 2 to 4. The minimum thickness of the blank
walls is specified, even though they are not involved in the engagement of the handling and securing devices;
they can be thicker than the minimum provided that their inner surfaces do not protrude into the corner
fitting cavity reserved for the engaging device.
The purpose of this document is to define some details of design vital to container interchange in automatic,
semi-automatic and conventional systems.
The strength and testing requirements specified in this document do not take any account of the stresses,
which can result from the practice of end-to-end coupling of containers.
NOTE The requirements of this document do not preclude the provision of additional facilities for lifting either
from the top or at the base of the freight container.

v
International Standard ISO 1161:2026(en)
Series 1 freight containers — Corner and intermediate fittings
— Specifications
1 Scope
This document establishes the basic dimensions and the functional and strength requirements of corner
and intermediate cast fittings for series 1 freight containers, i.e. containers which conform to ISO 668 and
ISO 1496 (all parts), with the exception of air mode containers (see ISO 8323).
Recognizing that there are containers which have ratings and dimensions different from ISO Series 1
containers referred to in ISO 668, which can be fitted with corner fitting of the same design as those
described in this document, or of another design, special arrangements for certification of any fittings for
such containers can be required.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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 1496-1, Series 1 freight containers — Specification and testing — Part 1: General cargo containers for
general purposes
ISO 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method
ISO 3874, Series 1 freight containers — Handling and securing
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Dimensional requirements
4.1 General
The dimensions and tolerances of the corner fittings shall conform to Figures 2, 3 and 4. A general view of
container fittings is shown in Figure 1.
Each series 1 container shall have two right-hand top corner fittings (on the right as the observer faces
either end of the container) and two left-hand top corner fittings, which are the mirror image of the right-
hand fittings.
The bottom corner fittings shall have a similar configuration except in respect of the end (i.e. front or rear
faces aperture.
45 ft containers shall have intermediate fitting in the 40 ft position (see Figure 1). The dimensions and
tolerances of the intermediate fittings shall conform to Figure 3 and Figure 4.

Figure 2 illustrates the left-hand top corner fitting and the right-hand top corner fitting as symmetrical.
Figure 3 illustrates the left-hand top intermediate fitting and the right-hand intermediate fitting as
symmetrical.
Figure 4 illustrates the left-hand bottom corner fitting, the intermediate fitting, the right-hand bottom
corner fitting and the intermediate fitting as symmetrical.
4.2 Detailed dimensional and manufacturing requirements
4.2.1 Sharp corners shall be removed as far as practicable (see Figure A.1).
4.2.2 Where the dimensions are not specified for inner and outer edges of apertures, these edges shall be
given a radius of: 3 (0 −1,5) mm,
4.2.3 At the junction of the two 6 mm outside edge radii with the 14,5 mm edge radius, the corner should
be rounded by blending the radiused edges, removing minimum amounts of material from the flat outer
faces and walls. Generally, it shall be spherical and the maximum radius shall be no more than 30 mm.
5 Strength requirements
The corner or intermediate fittings shall be designed, constructed and tested in such a manner and of such
materials as to enable them to pass the operating and testing requirements of ISO 1496-1 in addition to the
requirements in Clause 9 and Clause 10.
The mechanical properties of raw materials used shall result in producing corner fittings that meet or
exceed the following:
Yield strength: 275 MPa
Tensile strength: 480 MPa
a
Impact energy at – 20 °C 27 J
a
Impact energy at - 40 °C 21 J
Elongation: 25 %
Reduction of area: 40 %
a
Impact tests shall be in accordance with ISO 148-1.
The above are the minimum values for strength requirements. Certification societies may approve higher
values, but shall not approve lower values. Testing at temperatures lower than −40 °C may be approved, if
required.
Manufacturers are responsible for ensuring that quantities of undesirable eleme
...