ISO 4344:2022
(Main)Steel wire ropes for lifts — Minimum requirements
Steel wire ropes for lifts — Minimum requirements
This document specifies the minimum requirements for the manufacture and testing of stranded carbon steel wire ropes for lifts, made from bright and galvanized wire finish in various constructions from 6 mm to 38 mm diameter. It is applicable to ropes used for suspension duty on traction drive and roped hydraulic lifts, and for compensation and governor duties on passenger lifts, freight lifts, service lifts, and man lifts moving between guides. It is not applicable to ropes for — builder’s hoists, — temporary hoists not running between permanent guides, — cable-ways, — mine hoists.
Câbles en acier pour ascenseur — Exigences minimales
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 4344
Third edition
2022-12
Steel wire ropes for lifts — Minimum
requirements
Câbles en acier pour ascenseur — Exigences minimales
Reference number
ISO 4344:2022(E)
© ISO 2022
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ISO 4344:2022(E)
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© ISO 2022
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ISO 4344:2022(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 2
4.1 Material . 2
4.1.1 Wire. 2
4.1.2 Core . 2
4.1.3 Lubricant . 3
4.2 Rope manufacture . 3
4.2.1 General . 3
4.2.2 Wire joints . 4
4.2.3 Fibre core joints . 4
4.2.4 Lubrication . 4
4.2.5 Preformation and postformation . 4
4.2.6 Prestretching load limit . 4
4.2.7 Rope ends . 4
4.2.8 Rope construction . 4
4.2.9 Rope grade . 5
4.2.10 Type and direction of lay . 5
4.2.11 Lay length . 6
4.3 Designation and classification . 6
4.4 Dimensions . 6
4.4.1 Diameter . 6
4.4.2 Length . 7
4.5 Minimum breaking force . 7
4.6 Wire tensile strength . 8
4.7 Rope stretch . 8
5 Verification of requirements and test methods . 8
5.1 Materials . 8
5.2 Test on rope for diameter . . 8
5.2.1 Equipment . 8
5.2.2 Measured diameter . 8
5.2.3 Ovality . 9
5.2.4 Variation . 9
5.3 Test on rope for breaking force. 9
5.4 Test on rope for lubricant content . 9
5.5 Test on rope for wire tensile strength . 9
5.6 Additional test . . 9
6 Sampling and acceptance criteria .9
7 Information for use .9
7.1 Certificate . 9
7.1.1 General . 9
7.1.2 Test results . 10
7.2 Information for selection, installation, maintenance . 10
7.3 Discard criteria . 10
7.4 Marking . 10
7.5 Information recommended to be provided for an enquiry or an order . 10
Annex A (normative) Determination of lubricant content: gravimetric method.11
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ISO 4344:2022(E)
Annex B (normative) Tables of minimum breaking force values for the more common
classes, diameters and grade of ropes .14
Annex C (normative) Calculation of minimum breaking force .26
Annex D (informative) Calculation of approximate rope length mass, nominal metallic
cross-sectional area and approximate outer wire size .27
Annex E (informative) Determination of construction stretch and elastic stretch .28
Annex F (informative) Information for selection, storage, transportation, installation and
maintenance for lift ropes .30
Annex G (normative) Discard criteria for lift ropes .32
Annex H (informative) Information recommended to be provided with an enquiry or order .34
Bibliography .35
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ISO 4344:2022(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 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.
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 documents 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).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions 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 105, Steel wire ropes.
This third edition cancels and replaces the second edition (ISO 4344:2004), which has been technically
revised.
The main changes are as follows:
— added more rope grades commonly used in lifts and deleted rope grades rarely used in lifts;
— added more rope constructions commonly used in lifts;
— revised the requirement of lubricant content for rope cores;
— added the requirement of lubricant content for strands;
— revised diameter tolerances of steel core ropes;
— added the requirement of tensile strength for wires after rope making;
— added the information for rope selection, installation and maintenance;
— revised rope discard criteria.
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.
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ISO 4344:2022(E)
Introduction
This document was developed in response to a worldwide demand for a specification giving minimum
requirements for ropes for use on lifts.
It is desirable in such cases that the equipment designer, rope manufacturer or other competent person
be consulted prior to ordering a rope.
This document does not limit itself to those classes and constructions covered by the tables.
Other stranded rope constructions may also conform to the minimum requirements, and in such cases
the manufacturer would specify the minimum breaking force and rope grade.
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INTERNATIONAL STANDARD ISO 4344:2022(E)
Steel wire ropes for lifts — Minimum requirements
1 Scope
This document specifies the minimum requirements for the manufacture and testing of stranded
carbon steel wire ropes for lifts, made from bright and galvanized wire finish in various constructions
from 6 mm to 38 mm diameter.
It is applicable to ropes used for suspension duty on traction drive and roped hydraulic lifts, and for
compensation and governor duties on passenger lifts, freight lifts, service lifts, and man lifts moving
between guides.
It is not applicable to ropes for
— builder’s hoists,
— temporary hoists not running between permanent guides,
— cable-ways,
— mine hoists.
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 2232, Round non-alloy steel wires for general purpose wire ropes, large diameter wire ropes and mine
hoisting wire ropes —Specifications
ISO 3108, Steel wire ropes — Test method — Determination of measured breaking force
ISO 4101, Drawn steel wire for elevator ropes — Specifications
ISO 4345:1988, Steel wire ropes — Fibre main cores — Specification
ISO 4346, Steel wire ropes for general purposes — Lubricants — Basic requirements
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 17893, Steel wire ropes — Vocabulary, designation and classification
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 17893 and the following apply.
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/
3.1
composite steel core
CSC
wire rope core which is made of steel wires plus a fibre or polymer core
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ISO 4344:2022(E)
4 Requirements
4.1 Material
4.1.1 Wire
4.1.1.1 Wire properties and grades
Before rope making, wire properties shall be in accordance with ISO 4101 or ISO 2232.
Wire grades shall meet the following tensile strength grades given in Table 1.
Table 1 — Wire properties and grades
a b
Position of wires in the rope 1320 1370 1570 and 1620 1770 1960
Outer wires of outer strands ISO 4101 ISO 4101 ISO 4101 ISO 4101 ISO 2232
Inner, centre and core — — ISO 2232 ISO 2232 ISO 2232
Filler wires ISO 4101 ISO 4101 ISO 2232 ISO 2232 ISO 2232
a
Torsion properties are performed at 1370 MPa wire tensile strength grade.
b
Torsion properties are performed at 1770 MPa wire tensile strength grade.
Wire grades not given in Table 1, shall be subject to agreement between the purchaser and the
manufacturer.
4.1.1.2 Wire finish
Unless otherwise specified by the purchaser, the rope shall be made from bright wires.
Galvanized wire ropes shall be subject to agreement between the purchaser and the manufacturer, the
level of coating shall be Class B.
4.1.2 Core
4.1.2.1 General
The core shall be one of the following types:
a) fibre core;
b) steel core;
c) steel-based composite core, i.e. steel plus fibre or steel plus polymer;
d) non-metallic core, other than fibre-only.
Because of the large variety of existing designs, such as those prescribed by d), these core types should
be the subject of negotiation between purchaser and manufacturer.
4.1.2.2 Fibre core
Fibre cores (FC) including natural fibre cores (NFC), synthetic fibre cores (SFC) and solid polymer
cores (SPC), shall conform to ISO 4345. Natural fibre cores and synthetic fibre cores shall be doubly
closed (i.e. from yarn into strand and from strand into rope) and solid polymer cores can be one layer
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ISO 4344:2022(E)
or multiple layers. Unless otherwise specified by the purchaser, all the fibre cores shall conform to the
following requirements.
a) Natural fibre cores shall be manufactured from new sisal or manila vegetable fibre and, when
measured after rope closing in accordance with Annex A or ISO 4345:1988, Annex C, shall have a
lubricant content of 8 % to16 % by weight of the dry fibre material.
b) Synthetic fibre cores and solid polymer cores shall be manufactured from one or more than one of
the following materials: polypropylene, polyethylene, polyester or polyamide.
When measured after rope closing in accordance with Annex A or ISO 4345:1988, Annex C, synthetic
fibre cores for suspension ropes shall have a lubricant content of 6 % to 15 % by weight of the dry
material; synthetic fibre cores for governor ropes and compensating ropes shall have a lubricant
content of 3 % to 10 % by weight of the dry material.
c) The lubricant used in the manufacture of the fibre core shall not affect the lubricant used in rope
making.
d) Consideration of environmental humidity and temperature shall be given to potential rope
abnormal elongation and shrinkage when using natural fibre core ropes for governor and
compensating duties.
e) Fibre cores can include a core colour tracer for purposes of identifying the rope manufacturer, and
manufacturers can add their own information on the colour tracer, might include the manufacturer’s
name, brand, telephone number, etc.
4.1.2.3 Steel core
Steel cores (WC) include independent wire rope cores (IWRC), parallel closed wire rope cores (PWRC)
and wire strand cores (WSC).
Steel cores for ropes larger than 7 mm diameter shall not be a wire strand core.
4.1.2.4 Steel-based composite core
Typical steel-based composite cores (SCC) include composite steel cores (CSC) and polymer coated steel
cores (EPIWRC).
The fibres or polymers in steel-based composite cores shall be made from one or more than one of the
following materials: polypropylene, polyethylene, polyester or polyamide.
4.1.3 Lubricant
The lubricant shall be in accordance with ISO 4346.
4.2 Rope manufacture
4.2.1 General
All the wires in a strand shall have the same direction of lay and in the same layer shall be of the same
tensile strength grade.
In a new rope under tension on the closing machine, there shall be clearance between the outer strands.
The completed rope shall be evenly laid and free from unlaying, loose wires, distorted strands and
other irregularities. Indentations caused by forming toolings, e.g. dies, preformers and postformers,
are allowed.
When uncoiled, and under no load, the rope shall not be wavy.
For galvanized ropes, all the wires shall be galvanized, including those of a steel core where applicable.
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ISO 4344:2022(E)
4.2.2 Wire joints
Wires over 0,4 mm diameter shall, where necessary, have their ends joined by butt welding. All welds
shall be annealed.
Wires up to and including those of 0,4 mm diameter shall, where necessary, be joined by brazing or butt
welding or simply by ends being inserted into their correct position in the strand's formation.
The spacing between any two adjacent joints shall not be less than 18 times of the rope nominal
diameter.
4.2.3 Fibre core joints
Joints in fibre cores shall be made by splicing.
4.2.4 Lubrication
All of the strands of suspension, governor and compensating ropes shall be lubricated during the
stranding process. Unless otherwise specified by the purchaser, no lubricant shall be applied during the
final closing of the rope.
Unless otherwise specified by the purchaser, the rope shall meet the following requirements.
— For suspension and compensating ropes, when measured after rope closing in accordance with
Annex A, the outer strands shall have a lubricant content of 0,6 % to 1,8 % by weight of wires.
— For governor ropes, when measured after rope closing in accordance with Annex A, the outer
strands shall have a lubricant content of 0,5 % to 1,25 % by weight of wires.
4.2.5 Preformation and postformation
Unless otherwise specified by the purchaser, the ropes shall be preformed and/or postformed.
4.2.6 Prestretching load limit
Where rope is supplied in the pre-stretched condition, in order to avoid rope damage, the maximum
load to which the rope shall be subjected during the pre-stretching process shall not exceed 55 % of the
minimum breaking force of the rope. The loading may be through static or dynamic means.
4.2.7 Rope ends
The rope ends shall be secured such that they are prevented from unlaying.
4.2.8 Rope construction
The rope construction or class shall be agreed between the purchaser and the manufacturer and shall
be:
a) one of the more common rope constructions or classes covered by Tables B.1 to B.11 in Annex B,
where
Tables B.1 to B.8 apply to suspension ropes,
Tables B.1 to B.9 apply to governor ropes,
Tables B.1 to B.11 apply to compensating ropes, or
b) another single layer or parallel closed construction not covered by the tables but having no less
than six or not more than nine outer strands, or
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ISO 4344:2022(E)
c) another stranded rope construction specified by the purchaser other than those covered by a) and
b).
Where only the class is specified by the purchaser, the construction shall be decided by the manufacturer.
NOTE Each class of rope consists of a number of strand constructions, e.g. 8 × 19 class comprises 8×19W (1-
6-6+6), 8x19S (1-9-9), 8x21F (1-5-5F-10) and 8x25F (1-6-6F-12).
4.2.9 Rope grade
4.2.9.1 General
The rope grade shall reflect the tensile strength grades of the outer and inner wires respectively, and
shall be one of the following grades. Other rope grades shall be subject to the agreement between the
purchaser and the manufacturer.
4.2.9.2 Suspension ropes
Suspension ropes shall be of the following grades.
a) For traction drive lifts (see Tables B.1 to B.8):
— rope with fibre core: 1320/1620, 1370/1770, 1570/1770, 1620/1770, 1570, 1620, 1770, 1960;
— rope with steel core and parallel closed ropes: 1370/1770, 1570/1770, 1570, 1770, 1960.
b) For roped hydraulic lifts (see Tables B.1 and B.4):
— rope with fibre core: 1320/1770, 1370/1770, 1620/1770, 1570 and 1620, 1770;
— rope with steel core and parallel closed ropes: 1370/1770, 1570/1770, 1570, 1770, 1960.
4.2.9.3 Governor ropes
Governor ropes shall be of the following grades: 1320/1620, 1370/1770, 1620/1770, 1570, 1620, 1770,
1960. (See Tables B.1 to B.9.)
4.2.9.4 Compensating ropes
Compensating ropes shall have rope grades in accordance with 4.2.9.2. (See Tables B.1 to B.11.)
4.2.10 Type and direction of lay
The direction and type of rope lay shall be one of the following:
a) right ordinary lay (sZ);
NOTE 1 Formerly referred to as right hand ordinary (designated RHO) and right regular lay (designated
RRL).
b) left ordinary lay (zS);
NOTE 2 Formerly referred to as left hand ordinary (designated LHO) and left regular lay (designated
LRL).
c) right lang lay (zZ);
NOTE 3 Formerly referred to as right hand langs (designated RHL) or right lang lay (designated RLL).
d) left lang lay (sS).
NOTE 4 Formerly referred to as left hand langs (designated LHL) or left lang lay (designated LLL).
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ISO 4344:2022(E)
The direction and type of rope lay should be right ordinary lay (sZ), if not be specified by the purchaser.
4.2.11 Lay length
Unless otherwise specified by the purchaser, the lay length of the completed rope shall not exceed 6,75
times the nominal rope diameter.
4.3 Designation and classification
Rope classification and designation shall conform to the system requirements of ISO 17893.
4.4 Dimensions
4.4.1 Diameter
4.4.1.1 General
The nominal diameter shall be the dimension by which the rope is designated.
4.4.1.2 Tolerances
Unless otherwise specified by the purchaser, when measured in accordance with 5.2, the measured
diameter of the rope shall not exceed the tolerances given in Tables 2 to 4.
Considering the different requirements in lift designs, two grade of diameter tolerances are given
in Table 3 for suspension ropes of traction drive lifts and governor ropes with steel or steel-based
composite cores (including parallel closed ropes). Purchasers can choose the diameter tolerance
according to their needs.
Table 2 — Tolerances on diameter for suspension ropes for traction drive lifts and governor
ropes with cores of fibre or other non-metallic materials
Nominal rope Tolerance on nominal rope diameter
diameter
[%]
d
Max. at no load Min. at 5 % of F Min. at 10 % of F
[mm]
min min
≤10 +6 +1 0
> 10 +5 +1 0
Table 3 — Tolerances on diameter for suspension ropes of traction drive lifts and governor
ropes with steel or steel-based composite cores (including parallel closed ropes)
Nominal rope Tolerance on nominal rope diameter
diameter
Tolerance [%]
d
Max. at no load Min. at 5 % of F Min. at 10 % of F
[mm]
min min
≤10 +3 0 -1
Grade A
>10 +2 0 -1
≤10 +4 +1 0
Grade B
>10 +3 +1 0
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ISO 4344:2022(E)
Table 4 — Tolerances on diameter for suspension ropes of roped hydraulic lifts and
compensating ropes
Nominal rope diameter Tolerance on nominal rope diameter
d
[%]
[mm]
+6
6 ≤d < 8
0
+5
≥8
0
4.4.1.3 Permissible differences in diameter
The difference between any two of the four measurements when measured in accordance with 5.2 at
a load equivalent to 5 % or 10 % of the minimum breaking force shall not exceed the values given in
Table 5 for ovality.
The difference betw
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