ISO/DIS 23475-1

DRAFT INTERNATIONAL STANDARD
ISO/DIS 23475-1
ISO/TC 17/SC 17 Secretariat: SAC
Voting begins on: Voting terminates on:
2020-03-23 2020-06-15
Testing method for steel tyre cord —
Part 1:
General requirements
ICS: 77.140.65; 83.160.01
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ISO/DIS 23475-1:2020(E)
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ISO/DIS 23475-1:2020(E)
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Foreword ..........................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Dimension ................................................................................................................................................................................................................... 1

4.1 Cord diameter .......................................................................................................................................................................................... 1

4.1.1 Measure with micrometer ....................................................................................................................................... 1

4.1.2 Measure with profile projector ........................................................................................................................... 3

4.2 Unravelled Filament diameter ................................................................................................................................................... 4

4.2.1 Principle .................................................................................................................................................................................. 4

4.2.2 Apparatus ............................................................................................................................................................................... 5

4.2.3 Procedure ............................................................................................................................................................................... 5

4.2.4 Expression of results .................................................................................................................................................... 5

4.2.5 Test report ............................................................................................................................................................................. 5

4.3 Linear density .......................................................................................................................................................................................... 6

4.3.1 Principle .................................................................................................................................................................................. 6

4.3.2 Apparatus ............................................................................................................................................................................... 6

4.3.3 Procedure ............................................................................................................................................................................... 6

4.3.4 Test report ............................................................................................................................................................................. 6

4.4 Lay direction and lay length ........................................................................................................................................................ 6

4.4.1 Lay direction/direction of lay ............................................................................................................................... 6

4.4.2 Trace method for lay length ................................................................................................................................... 7

4.4.3 Untwisting method for lay length ..................................................................................................................... 8

5 Process property .................................................................................................................................................................................................. 9

5.1 Straightness ............................................................................................................................................................................................... 9

5.1.1 Principle .................................................................................................................................................................................. 9

5.1.2 Apparatus ............................................................................................................................................................................... 9

5.1.3 Procedure ............................................................................................................................................................................... 9

5.1.4 Test Report ............................................................................................................................................................................ 9

5.2 Arc height ..................................................................................................................................................................................................10

5.2.1 Principle ...............................................................................................................................................................................10

5.2.2 Apparatus ............................................................................................................................................................................10

5.2.3 Procedure ............................................................................................................................................................................10

5.2.4 Test report ..........................................................................................................................................................................10

5.3 Flare ...............................................................................................................................................................................................................10

5.3.1 Principle ...............................................................................................................................................................................10

5.3.2 Apparatus ............................................................................................................................................................................10

5.3.3 Procedure ............................................................................................................................................................................10

5.3.4 Test report ..........................................................................................................................................................................11

5.4 Residual torsion ..................................................................................................................................................................................11

5.4.1 Principle ...............................................................................................................................................................................11

5.4.2 Apparatus ............................................................................................................................................................................11

5.4.3 Procedure ............................................................................................................................................................................11

5.4.4 Test report ..........................................................................................................................................................................11

6 Mechanical property .....................................................................................................................................................................................12

6.1 Breaking load and elongation at fracture .....................................................................................................................12

6.1.1 Principle ...............................................................................................................................................................................12

6.1.2 Apparatus ............................................................................................................................................................................12

6.1.3 Procedure ............................................................................................................................................................................12

6.1.4 Test report ..........................................................................................................................................................................13

6.2 Elongation between defined forces (EDF) ...................................................................................................................13

6.2.1 Principle ...............................................................................................................................................................................13

6.2.2 Apparatus ............................................................................................................................................................................14

6.2.3 Procedure ............................................................................................................................................................................14

6.2.4 Test report ..........................................................................................................................................................................15

6.3 Loop test (Elasticity) .......................................................................................................................................................................15

6.3.1 Principle ...............................................................................................................................................................................15

6.3.2 Apparatus ............................................................................................................................................................................15

6.3.3 Procedure ............................................................................................................................................................................16

6.3.4 Test report ..........................................................................................................................................................................17

7 Determination of mass and composition of coating .....................................................................................................17

7.1 X-Ray fluorescence spectroscopy .........................................................................................................................................17

7.1.1 Principle ...............................................................................................................................................................................17

7.1.2 Apparatus ............................................................................................................................................................................17

7.1.3 Reagents ...............................................................................................................................................................................17

7.1.4 Preparation of test samples .................................................................................................................................18

7.1.5 Procedure ............................................................................................................................................................................18

7.1.6 Expression of results .................................................................................................................................................18

7.1.7 Test report ..........................................................................................................................................................................19

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This document was prepared by Technical Committee ISO/TC17, Steel, Subcommittee SC 17, Steel wire

This part of International standard specifies test methods of steel cords which are used for tyre

reinforcement. Dimension, process properties, mechanical properities and coating test method are all

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

For the purposes of this document, the terms and definitions given in ISO 17832 apply.

Hold the sample between two parallel circular faced anvils of a micrometer. Close the movable anvil

gradually and gently until it is in contact with the specimen. Read the value on the micrometer.

A precision disk micrometer with non-rotate spindle is suggested. This micrometer may have a hole

Anvil type: the dimeter of the anvils shall be greater than one lay length (min. 20 mm in diameter).

a) Clean the surface of the anvils with clean paper. Verify whether the micrometer reads 0,000 when

b) Fuse a specimen to a length about 150 mm and take care that cord end is well secured and no

c) Close the movable anvil gradually and gently until it is in contact with the specimen. For normal

cords, stop rotating the spindle when 3 ‘click’ are heard and for HE, HI and OC constructions only 1

d) Axially rotate the sample between repeated measurements in order to find the maximum diameter

Specimens of a cord sample are successively put on the optical microscope. A silhouette of the cord is

projected on the screen. The thickness of the specimen is measured by moving the abscissa axis of the

4.1.2.2.2 Sample holder, A frame on which two magnets are fixed in order to position the test

a) Fuse a specimen to a length about 100mm, ensure that fuse is well done in order to prevent the

cord ends from any unravelling. Put the specimen on the sample holder and ensure that is fixed by

b) Bring the sample into sample holder and adjust the focal distance. Make the sample being projected

c) Rotate the sample until the maximum profile is being projected on the screen. Move the micrometer

table until the horizontal reference line contacts two consecutive waves. (figure3).

d) Reset the micrometer. Move the stage until X axis contacts the opposite wave (Figure 4). Record

the reading as maximum diameter (D . If there are two waves on the opposite side, measure the

e) Turn the specimen through 90 degrees until a minimum diameter is obtained, record the minimum

diameter D . Repeat the step c and d and record the reading as minimum diameter (D ). If there are

NOTE This test method is generally used for open cords and HI cords or for other cord types that are

A sample is held between two parallel blade anvils of a micrometer. The movable anvil is closed

gradually and gently until it is in contact with the specimen. Read the value on the micrometer.

a) Clean the surface of the anvils with clean paper. Verify whether the micrometer reads 0,000 when

b) Cut the wire approximately 100 mm in length. Position the specimen in the center of the anvils.

c) The movable anvil is closed gradually and gently until it is in contact with the specimen. Read the

d) Measure on the same section of the specimen until Max diameter (d ) and Min diameter (d ) is found.

A straight section of the cord of a predefined length, generally 1 m, is weighted using an analytical

NOTE Make sure the cord is straightened before cutting. For normal construction, the pretension is

b) Verify the balance, coil the sample and weight it, record the weight as linear density.

Hold the cord vertically and verify whether the filaments or strands around the central axis are having

The cord, strand or wrap has an “S” or left-handed lay if, when held vertically, the spirals around the

central axis of the cord or strand conform in direction of slope to the central portion of the letter “S”;

and “Z” or right-handed lay if the spirals conform in direction of slope to the central portion of the letter

Through the impacted trace of the wire, calculate the lay length by measuring the distance of multiple

Pencil, Paper, White paper or carbon paper, Vernier caliper (which can be read to the nearest 0,5mm)

a) Fuse a specimen of cord approximately 300 mm in length. Place the specimen on the clean and

b) Place a sheet of white paper or carbon paper over a straight-length section of the specimen and rub

L: is the distance between the first and eleventh node, express in millimetre (mm).

A specified length of specimen of cord or strand is untwisted until the elements to be determined are

parallel. The length of lay can be calculated by the specified length divided by the untwisted turns.

a) Place a straight specimen in the lay length tester being clamped in such a manner that no slippage

will occur. The specimen shall be placed under a tension just enough to keep the specimen straight,

but no more than 20 N. If the cord has a wrap then this filament shall be cut in the middle of the

b) Set the counter at zero. The twist is removed by turning the rotatable clamp until the components

of the external layer of the specimen are complete separated. These components shall be parted

with a needle or the blade of a spatula (starting at the non-rotatable clamp and moving to the

rotatable clamp) to avoid the entanglement of components and to confirm that all the twist has

c) If it is the multiple layers construction and the lay length of core strand need to be measured, the

operation as described above shall be repeated without unloading the cord. The number of turns to

NOTE For M x N constructions, after untwisting the first layer of the cord, there is a change in length of the

remaining elements. The gauge length should be decided through consultation by buyer and seller.

Keep the cord at nature status, the position of the cord between two parallel straight lines, which are

a prescribed distance apart, is observed, the cord shall be considered straight, when it is not touching

5.1.2.1 Spool mounting device, enabling the spool to rotate freely on a horizontal axis

Without cutting the specimen from the spool, pull out a 6 m length of cord (or other length agreed

upon between the buyer and seller) and position it, residual torsion free and with no tension applied,