ISO 17832:2018

INTERNATIONAL ISO
STANDARD 17832
Second edition
2018-05
Non-parallel steel wire and cords for
tyre reinforcement
Fils d'acier et cordes non parallèles pour le renfort de pneumatiques
Reference number
©
ISO 2018
© ISO 2018
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ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 2
4.1 Classification based on tensile strength . 2
4.2 Classification based on cord structure . 3
4.3 Classification based on cord type . 4
5 Designation and ordering . 4
5.1 Cord structure . 4
5.2 Cord tensile strength . 5
5.3 Cord type . 5
5.4 Length and direction of lay . 5
5.5 Coating type . 6
6 Requirements . 6
6.1 General . 6
6.2 Dimensions, mass and tolerances . 6
6.2.1 Diameter of cord . 6
6.2.2 Linear density . 6
6.2.3 Tolerances . 6
6.3 Welds and splices . 6
6.4 Mechanical properties . 7
6.4.1 Breaking load and elongation at fracture . 7
6.4.2 Structural elongation . 7
6.5 Technological properties . 7
6.5.1 Straightness . 7
6.5.2 Arc height . 7
6.5.3 Residual torsion . 7
6.5.4 Flare . 7
6.5.5 Steel cord elasticity . 7
6.5.6 Rubber penetration . 8
6.6 Brass coating . 8
6.6.1 Mass fraction of brass coating . 8
6.6.2 Thickness of coating . 8
6.6.3 Composition of brass . . 8
6.7 Adhesion force . 8
6.8 Constructions and properties . 8
7 Sampling . 9
8 Packing. 9
8.1 General . 9
8.2 Spools . 9
8.3 Packaging .10
Bibliography .18
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 on 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 the following
URL: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 17, Steel wire
rod and wire products.
This second edition cancels and replaces the first edition (ISO 17832:2009), which has been technically
revised.
The following changes have been made:
— tensile strength for UT, ST and NT constructions has been updated;
— HI construction has been added;
— the tolerance for lay length has been narrowed from “±10 %” to “±5 %”;
— the tolerance of residual torsion for HE construction has been narrowed from ±4 torsion/6 m
to ±3 torsion/6 m;
— the tolerance for spool length has been narrowed;
— the weld breaking load for HT, ST and UT constructions has been increased.
iv © ISO 2018 – All rights reserved

INTERNATIONAL STANDARD ISO 17832:2018(E)
Non-parallel steel wire and cords for tyre reinforcement
1 Scope
This document specifies the definition and requirements of non-parallel steel wire and cords for tyre
reinforcement.
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 2859-1, Sampling procedures for inspection by attributes — Part 1: Sampling schemes indexed by
acceptance quality limit (AQL) for lot-by-lot inspection
ISO 3951-1, Sampling procedures for inspection by variables — Part 1: Specification for single sampling
plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection for a single quality characteristic
and a single AQL
ISO 3951-2, Sampling procedures for inspection by variables — Part 2: General specification for single
sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection of independent quality
characteristics
ISO 3951-3, Sampling procedures for inspection by variables — Part 3: Double sampling schemes indexed by
acceptance quality limit (AQL) for lot-by-lot inspection
ISO 3951-5, Sampling procedures for inspection by variables — Part 5: Sequential sampling plans indexed
by acceptance quality limit (AQL) for inspection by variables (known standard deviation)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at https: //www .iso .org/obp
3.1
filament
metal fibre with a metallic alloy coating used as an individual element in a strand (3.2) or cord (3.3)
3.2
strand
group of filaments (3.1) combined together to form a unit product for further processing
3.3
cord
formed structure composed of two or more filaments (3.1) when used as an end product, or a
combination of strands (3.2) or filaments and strands
3.3.1
single-strand cord
cord (3.3) formed by twisting two or more filaments (3.1) together
3.3.2
M+N type cord
cord (3.3) formed by twisting a number of non-concentric filaments (3.1) around a number of parallel
filaments
Note 1 to entry: The cross-section is not round and varies along the length.
3.3.3
layer cord
cord (3.3) formed by adding layers around a core
Note 1 to entry: The layers can be filaments or strands.
3.3.4
multi-strand cord
cord (3.3) formed by twisting two or more strands (3.2) together
3.4
wrap
filament (3.1) wound helically around a steel cord (3.1)
3.5
direction of lay
helical disposition of the components of a strand (3.2) or cord
Note 1 to entry: The strand or cord has an “S” or left-hand lay, when held vertically, if the spirals around the
central axis of the strand or cord conform in direction of slope to the central portion of the letter “S”.
Note 2 to entry: The strand or cord has a “Z” or right-hand lay if the spirals conform in direction of slope to the
central portion of slope of the letter “Z”.
3.6
length of lay
axial distance required to make a 360° revolution of any element in a strand (3.2) or in a cord (3.3)
Note 1 to entry: The length of lay is expressed in millimetres.
4 Classification
4.1 Classification based on tensile strength
Steel cord is supplied in levels of tensile strength (see Figure 1), designated as follows:
— NT: normal standard (or regular) tensile strength cord;
— HT: high tensile strength cord;
— ST: super tensile strength cord;
— UT: ultra tensile strength cord.
2 © ISO 2018 – All rights reserved

Key
X filament diameter, mm 1 solid line indicates target value
Y filament tensile strength, MPa 2 dashed line indicates tolerance range
NOTE The target value is determined by agreement between the manufacturer and the purchaser.
Figure 1 — Tensile strength levels
Figure 1 gives the tensile strength levels of wet-drawn filaments. The cord breaking load is calculated
from the filament number, lay length and cabling loss. For example, cord construction 2x0,30ST 14/S is
calculated by Formula (1):
F = n × ( f × cos α) × (1 − C) (1)
where
F is the breaking load of cord construction 2x0,30ST 14/S, in mega pascals;
f is the breaking load of 0,30ST, in mega pascals;
α is the cabling angle, in degrees;
n is the number of filament;
C is the cabling loss on tensile strength (e.g. 4 %).
4.2 Classification based on cord structure
The main classification based on cord structure is categorized by the following four structures:
— single-strand cords;
— M+N type cords;
— layer cords;
— multi-strand cords.
4.3 Classification based on cord type
The main classification based on cord type is categorized by the following four types:
— HE: high-elongation cord;
— OC: open cord;
— CC: compact cord;
— WC: wavy cord, a cord with filaments preformed in 2 or 3 dimensional wavy shape in order to
improve rubber penetration;
— HI: high impact cord.
Another detailed classification may be used if there is mutual agreement between the manufacturer
and the purchaser.
5 Designation and ordering
A tyre cord construction is normally defined by
— cord structure,
— cord tensile strength,
— cord type,
— length and direction of lay, and
— coating type.
5.1 Cord structure
The description of the cord structure follows the sequence of manufacture of the cord, i.e. starting with
the innermost strand or wire and moving outwards.
The full description of the cord structure is given by the following formulas:
(N × X) × D + (N × X) × D + (N × X) × D + D, or
(N × X) × D/(N × X) × D/(N × X) × D + D for compact cords, and
(N × N) × D + D
where
N is the number of strands;
X is the number of filaments;
D is the nominal diameter of wires, expressed in millimetres.
EXAMPLE 1 (1 × 3) × 0,22 + (1 × 9) × 0,22 + (1 × 15) × 0,22 + 0,15.
When N or F equals 1, they should not be included.
EXAMPLE 2 3 × 0,22 + 9 × 0,22 + 15 × 0,22 + 0,15.
4 © ISO 2018 – All rights reserved

If the diameter D is the same for two or more parts in sequence, it shall only be stated at the end of the
sequence.
The diameter of the spiral wrap shall always be stated separately.
EXAMPLE 3 3 + 9 + 15 × 0,22 + 0,15.
When the innermost strand or wire is identical to the adjacent strand or wires, the formula may be
simplified by stating only the sum of the identical components and brackets need not be used.
EXAMPLE 4 0,22 + 6 × 0,22 + 6 × (0,22 + 6 × 0,22) becomes 7 × 7 × 0,22.
5.2 Cord tensile strength
There are four levels of tensile strength: NT, HT, ST and UT as defined in 4.1. The tensile class of the
spiral wrap is not governed by the tensile class levels.
5.3 Cord type
See 4.3
5.4 Length and direction of lay
The sequence or order in the designation follows the sequence of manufacturing, i.e. starting with the
innermost strand and moving outwards.
EXAMPLE 1
3 + 9 + 15 × 0,175 + 0,15
5/10/16/3.5 SSZS
5 S: lay length and direction of the strand 3 × 0,175
10 S: lay length and direction of the strand + 9 × 0,175
16 Z: lay length and direction of the strand + 15 × 0,175
3,5 S: lay length and direction of the spiral wrap
EXAMPLE 2
7 X (3 + 9 + 15 × 0,175) + 0,20
(5/10/16)/(5/10/16)/38/5 SSS/ZZZ/S/Z
5 S: lay length and direction of the innermost strand 3 × 0,175
10 S: lay length and direction of the innermost strand + 9 × 0,175
16 S: lay length and direction of the innermost strand + 15 × 0,175
5 Z: lay length and direction of the adjacent strand 3 × 0,175
10 Z: lay length and direction of the adjacent strand + 9 × 0,175
16 Z: lay length and direction of the adjacent strand + 15 × 0,175
38 S: lay length and direction of the cable
5 Z: lay length and direction of the spiral wrap
5.5 Coating type
There are two classic types of brass coating: high-copper coating and normal copper coating, as listed
in Table 2. More advanced metallic alloy coatings such as Cu-Zn-Co are possible.
6 Requirements
6.1 General
Specified tests are mainly conducted in accordance with internationally agreed methods for steel tyre
cords, such as ASTM D2229-10, ASTM D2969-04, BISFA, JIS G 3510, etc.
6.2 Dimensions, mass and tolerances
6.2.1 Diameter of cord
The diameter of the circumscribed circle of cord, in millimetres, and detailed requirements are listed
in Table 5.
6.2.2 Linear density
The linear density, i.e. the mass of a 1 m length of cord, in grams per metre (g/m), and detailed
requirements are listed in Table 5.
6.2.3 Tolerances
The tolerance of the cord length shall conform to Table 1.
Tolerance of filament diameter: ±10 µm.
Tolerance of lay length: ±5 %.
Tolerance of residual torsion of co
...