KR20120024609A - Tyre bead wire and process for production thereof - Google Patents

Abstract

The present invention uses a general-purpose carbon steel wire rod having a carbon content of 0.61% or more and 0.65% or less in weight% to a predetermined final extension wire diameter suitable for a bead wire. Provided are a bead wire for tires and a method for producing the same, which are capable of extending to a line. Therefore, carbon steel wire containing from 0.61% to 0.65% by weight, and having a diameter of 5.5 mm to 6.5 mm, has a true strain of 2.0 to 4.0 by stretching treatment for one wire. The line is stretched to a predetermined final stretched wire diameter to form a pearlite structure in which the gap between ferrite and cementite is narrow.

Description

Bead wire for tire and manufacturing method {TYRE BEAD WIRE AND PROCESS FOR PRODUCTION THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bead wire for a tire to be used for the production of a bead core, which is a reinforcing material for automobile tires made of carbon steel wire, and a manufacturing method thereof.

The bead wire for tires is required to be tough and high in durability, and in general, the diameter of the bead wire is 1.55 mm φ , the tensile strength is 1880 N / mm 2 or more, and the diameter of the bead wire is 0.94 mm φ . The thing of 1840 N / mm <2> or more of tensile strength is used. In this way, the bead wire requires a high tensile strength, so as a hard wire bus bar, a wire diameter of mainly 5.5 mm φ and carbon content of 0.69 to 0.86% by weight of a high carbon steel wire rod is used. It is made by extending the line with a total reduction rate of about 92 to 97%.

The high carbon steel wire rod is usually wire-stretched and patterned by repeating the wire rod having a diameter of 5.5 to 6.5 mm of the pearlite structure that has been adjusted and cooled after hot rolling as necessary. It is set as the wire diameter of 3.0-2.0 mm in diameter which extends a final line | wire. After the wire is finally stretched to the wire diameter, a bluing treatment is performed, the plating treatment is performed, and the wire is wound, and a steel cord used as a reinforcing material such as a radial tire or a belt conveyor. It is intended to manufacture. The method of manufacturing this kind of steel cord is described in patent document 1, for example.

In addition, patent document 2 describes the method of performing an elongation process of a line secondly, skipping an intermediate patterning process. As described in Patent Literature 2, by adding a mechanical external force to the steel and deforming, the temperature of the steel is raised, whereby drying of borax in the stretching process with respect to the secondary line is made favorable, and It is possible to extend the secondary wire without generating any wires or disconnection.

Japanese Patent Laid-Open No. 1995-3338 Japanese Patent Application Laid-Open No. 2008-284581

By the way, in order to omit the intermediate patterning process and to manufacture a wire having a predetermined diameter only by the primary wire extension processing (omit the secondary wire extension processing), the wire extension processing is performed by preventing the disconnection due to high processing. In order to maintain the following strength at a predetermined strength, it is necessary to use a bus bar having a special wire diameter of which the wire diameter of the bus bar is thinner than 5.5 mm for general use. However, the wire rod of a special wire diameter (for example, a wire diameter of 5.0 mm or less) of a small quantity production repeats a line extension process and a patterning process compared with the case where the general-purpose 5.5 mm wire diameter wire rod is used. Since it is necessary, the price of a bus bar will become high, and there exists a problem that the production cost of a bead wire and also a tire rises.

Also, in recent years, the use of tires has been increased from the use of the environment from the use of the tire once, and the rate of use of the tire twice is increased, and even after adhesion for a long time in the adhesion of the bead wire with the surrounding rubber. The demand for adhesive strength and durability is increasing.

In terms of production, the bus bar of the raw material is generally welded to the wire rod being used for continuous production and the wire rod to be used next by welding, and the wire extension processing is performed. However, the welding is heated at a high temperature as the carbon content increases. There is a problem in that the tissue change of the damaged part is remarkable, which greatly affects strength and toughness.

This invention is made | formed in order to solve the above-mentioned conventional problem, The bead wire does not perform a patterning process using the carbon steel wire of the general-purpose wire diameter of carbon content of 0.61% or more and 0.65% or less by weight%. It is an object of the present invention to provide a bead wire for tires and a method of manufacturing the same, which enable the wire to be stretched by a step up to a predetermined final stretch wire diameter.

A feature of the invention of the bead wire for tires according to claim 1 is that carbon steel wire containing from 0.61% or more and 0.65% or less in carbon by weight and having a diameter of 5.5 mm to 6.5 mm by one stretching treatment for one line. In the range of true strain 2.0 to 4.0, the line is stretched to a predetermined final stretched wire diameter, and the pearlite structure is formed by narrowing the gap between ferrite and cementite. .

A feature of the invention of the bead wire for tires according to claim 2 is that the wire is stretched to 0.94 to 1.30 mm phi by the stretching treatment for one line in claim 1.

A feature of the invention of the method for producing a bead wire for tires according to claim 3 is that a carbon steel wire rod having a diameter of 5.5 mm to 6.5 mm containing carbon in weight% of 0.61% or more and 0.65% or less, and a true strain of 2.0 to 4.0. In this range, the wire is stretched by a step up to a predetermined final stretched wire diameter, and the wire rod after stretching the wire is blued and then plated.

The characteristic of the invention of the manufacturing method of the bead wire for tires which concerns on Claim 4 WHEREIN: In line 3, the carbon steel wire of 5.5 mm in diameter is extended | stretched to the final elongation wire diameter of 0.94-1.30 mm ( phi ).

The characteristic of the invention of the manufacturing method of the bead wire for tires which concerns on Claim 5 WHEREIN: In line 3, the carbon steel wire rod of 6.5 mm in diameter is extended | stretched to the final extension wire diameter of 1.5-2.20 mm ( phi ).

According to the invention of the bead wire for tires according to claim 1, carbon steel wire containing from 0.61% to 0.65% by weight and having a diameter of 5.5 mm to 6.5 mm is subjected to elongation treatment for one wire, In the range of true strain rate 2.0-4.0, since the line is stretched to a predetermined final stretched wire diameter and has a pearlite structure in which the gap between ferrite and cementite is narrow, tension is achieved while using a general-purpose carbon steel wire having a general wire diameter. A useful bead wire for tires having excellent strength, good adhesion to the surrounding rubber of the bead wire, and no disconnection at the time of extension to the wire and disconnection at the welding location can be obtained.

According to the invention of the bead wire for tire according to claim 2, since the wire is stretched to 0.94 to 1.30 mm φ by one stretching process, the bead core having a wire diameter suitable for producing the bead core can be easily obtained. It can also be obtained efficiently.

According to the invention of the method for producing a bead wire for tires according to claim 3, a carbon steel wire rod having a diameter of 5.5 mm to 6.5 mm, containing carbon in weight% of 0.61% or more and 0.65% or less, has a true strain of 2.0 to 4.0. In the range, since the wire is stretched by a step up to a predetermined final stretched wire diameter, it is possible to perform stretching of the wire at a high reduction ratio of a carbon steel wire having a relatively low carbon content without performing a patterning process. The carbon steel wire rod having a wire diameter (5.5 to 6.5 mm in diameter) can be stretched by a step up to the final stretch wire diameter suitable for the bead wire, without causing disconnection and ensuring the required tensile strength.

In addition, since the carbon content is low and the carbon steel wire rod is in a soft state, the workability at the time of extending the carbon steel wire rod can be improved, and the productivity can be increased while the wire rod is continuously stretched. It is possible to easily perform welding at the time of joining the bus bar which is necessary for continuous production of the bus bar in use and the bus bar to be used next time, and it is possible to prevent the disconnection at the weld section.

According to the invention of the method for producing a bead wire for tires according to claim 4, since the wire was stretched to a final extension wire diameter of 0.94 to 1.30 mm φ , the carbon steel wire having a diameter of 5.5 mm was used. A carbon steel wire can be used, and the equipment which performs a patterning process is not required, and a bead wire can be manufactured in low cost.

According to the invention of the method for producing a bead wire for tires according to claim 5, since the wire is stretched to a final extension wire diameter of 1.5 to 2.20 mm φ of carbon steel wire having a diameter of 6.5 mm, the general 6.5 mm wire diameter A carbon steel wire can be used, and the equipment which performs a patterning process can be made unnecessary, and a bead wire can be manufactured in low cost.

1 is a diagram showing a layer of ferrite and cementite aligned by extension of lines.
It is a figure of the Example which showed the manufacturing process in the bead wire manufacturing method for tires of this invention.
3 is a photograph of the surface of the bead wire in a state where the plating layer of the surface of the bead wire manufactured as shown in FIG. 2 is peeled off.

Hereinafter, the tire bead wire manufacturing method which concerns on embodiment of this invention is demonstrated.

The bead wire used for the tire of an automobile is strong and high durability is calculated | required. The strength of the bead wire can be increased by extending the wire and reducing the wire diameter of the patterned wire rod of the fine pearlite structure (two-phase structure of ferrite Fe and cementite Fe 3 C). Tires employing bead cores produced using wires can contribute to high strength, high toughness and light weight. As shown in FIG. 1, the crystals of cementite Fe 3 C and ferrite Fe having high strength are stretched and aligned in the direction of linear stretching by line stretching, the width of the ferrite phase is narrowed, and the strength is increased. Because it becomes. In addition, as the wire diameter is thinned by the wire extension, the strength increases.

However, the thinner the wire diameter, the harder the wire rod and the less the flexibility. Therefore, there is a limit to the wire diameter that can be thinned by one line extension processing. Therefore, in order to obtain a desired wire diameter, after performing the wire stretching to a predetermined wire diameter, it is necessary to perform a patterning process to return the wire to a fine pearlite structure suitable for the wire stretching, and then to perform the wire stretching again. There is. Thus by repeating the same processing, for example, a wire of 5.5mm φ on a general-purpose wire diameter, and extending the line to 1.20mm φ, Thereafter, in order to give it the height required for the steel wire, 380 ℃ to 480 ℃ In order to perform a bluing process and to improve adhesiveness with the surrounding rubber of a bead wire, after performing a plating process, a bead wire is wound up in a coil form to a winder. However, in such a method, it is necessary to provide the installation which performs a patterning process in a manufacturing facility.

In order to eliminate the need for equipment for patterning and to allow the wire rod to be stretched to a desired wire diameter (2.20 to 0.94 mm φ ) suitable for the bead wire by stretching treatment for one wire, the wire diameter This small bus bar, for example, a bus bar having a wire diameter of 4.0 mm φ or 4.5 mm φ may be used. However, in order to do this, a bus bar having a special wire diameter must be obtained from a steelmaker.

So, in this embodiment, as a bus | wire for a bead wire, it is carbon steel whose carbon content is lower than the conventional carbon content of 0.61-0.65 weight%, and does not perform an intermediate patterning process on the wire material of 5.5-6.5 mm of wire diameters. Instead, the wire can be stretched by a process up to a predetermined final stretched wire diameter (2.20 to 0.94 mm φ ) suitable for the bead wire. Compared with the conventional reduction rate, the reduction rate is increased. However, since the wire content of the wire rod is lower than that of the conventional one and the material is softer than the conventional one, it is possible to extend the wire with a high reduction rate. Further, by extending the wire with a high reduction ratio of carbon steel having a low carbon content, the gap between the ferrite Fe and the cementite Fe3C shown in FIG. 1 is narrow, and the structure is fine and smooth. It is possible to obtain a bead wire that can secure toughness and also have good adhesion to the surrounding rubber of the bead wire, and can prevent disconnection at the time of extension to the wire and disconnection at the welding location.

Fig. 2 shows the manufacturing process of the bead wire, and the carbon steel (wire material) having a wire diameter of 5.5 to 6.5 mm and a carbon content of 0.61 to 0.65 weight% is taken out from the winding machine (step 10), and the surface is descaled. The oxide film was removed (step 11), then passed through the coating liquid attachment device, and the coating liquid was attached to the surface of the wire rod (step 12) to be dried. Subsequently, by the dry wire extension apparatus 30 which arrange | positioned the wire continuously, the wire | line | wire is carried out to predetermined final extension wire diameter (2.20-0.94 mm phi ) by one process in the range of true strain rate 2.0-4.0. After the stretching processing (step 13) is performed, the winding machine is wound up (step 14).

At this time, when the wire diameter is 5.5 mm, the final extension wire diameter for stretching the wire by one step is preferably about 0.94 to 1.30 mm φ , and when the wire diameter is 6.5 mm, As for the final elongation wire diameter which extends a line, about 1.5-2.20 mm ( phi ) is preferable.

Subsequently, the wire rod having the wire stretched to the final stretched wire diameter is taken out from the winding machine (step 20), the bluing process (step 21) is performed by the bluing processing apparatus, and the plating process (step 22) is performed by the plating processing apparatus. By winding the winding machine (step 23), the bead wire for a tire is manufactured.

By the way, in the continuous production of the wire rod, in order to continuously produce the material in use and the material to be used next time, the end of the material in use and the beginning of the material to be used next are It is necessary to join by welding. Productivity is greatly affected by the occurrence rate of disconnection at the welding location where the tensile load or bending is weaker than the usual location. However, as the carbon content increases, the welding has a significant change in the structure of the welding location and the parts exposed to high temperatures near it. After welding, tempering is performed, but the influence remains, which greatly affects tensile strength and toughness. On the other hand, when carbon content becomes low, the disconnection generation rate resulting from welding will reduce, and productivity will improve.

In addition, the adhesive force between the bead wire and the rubber is a physical bonding force due to the chemical bonding force due to the chemical reaction between the rubber and the plating of the bead wire surface and the anchoring effect on the wrinkles of the bead wire surface. Is determined. Therefore, although limited, it becomes possible to raise adhesive force by raising an anchoring effect. In particular, when the adhesive interface between the rubber and the bead wire surface is deteriorated due to high heat, high moisture, and repeated deformation due to severe tire running, the physical adhesive force due to the anchoring effect is effective. Exert.

[Example]

Next, the structure and effect of this invention are concretely demonstrated to an Example.

Example 1

As shown in Table 1, the raw material bus bar used the hard steel wire rod whose wire diameter prescribed | regulated to JIS G3506 SWRH62A is 5.5 mm ( phi ). Chemical components are C: 0.63%, Si: 0.21%, Mn: 0.52%, and remainder is Fe and an unavoidable impurity. The raw material is removed from the surface oxide film by a descaling device, and then passed through the coating liquid attachment device, whereby the coating liquid is adhered to the surface of the wire rod and dried. Subsequently, the wire rod was continuously reduced by a single wire stretching process to a predetermined wire diameter of 1.20 mm phi in the range of true strain rate of 2.0-4.0 by the dry wire extension apparatus arrange | positioned continuously. The wire rod which stretched the wire wound up by coiling by the winding machine, sent out the wound wire rod, passed through the inside of a 430 degreeC bath, and blued, and performed the plating process after that, and manufactured the bead wire.

Comparative Example 1

As shown in Table 1, the raw material bus bar used the hard steel wire rod whose wire diameter prescribed | regulated to JIS G3506 SWRH72A is 5.5 mm ( phi ). The chemical components are C: 0.71%, Si: 0.22%, Mn: 0.49%, and the balance is Fe and unavoidable impurities. The raw material is removed from the oxide film on the surface by a descaling apparatus, and then passed through the coating liquid applying apparatus, thereby coating the coating liquid on the surface of the wire rod. Subsequently, it was exempted by one line extension process to the predetermined line diameter which is a wire diameter of 1.20 mm ( phi) by the dry wire extension apparatus which arranged the wire material continuously. The wire rod in which the wire was stretched was wound into a coil shape by a winding machine, the wound wire rod was taken out, passed through a bus at 430 ° C., and then blueed, and then the plating treatment was performed to produce a bead wire.

Comparative Example 2

As shown in Table 1, the raw material bus bar used the hard steel wire rod whose wire diameter prescribed | regulated to JIS G3506 SWRH72A is 4.5 mm ( phi ). The chemical components are C: 0.72%, Si: 0.21%, Mn: 0.51%, and the balance is Fe and unavoidable impurities. The raw material is removed from the oxide film on the surface by a descaling apparatus, and then passed through the coating liquid applying apparatus, thereby coating the coating liquid on the surface of the wire rod. Subsequently, the wire rod was exempted by one line stretching process up to a predetermined wire diameter of 1.20 mm phi by a dry wire elongation apparatus arranged continuously. The wire rod in which the wire was stretched was wound into a coil shape by a winding machine, the wound wire rod was taken out, passed through a bus at 430 ° C., and then blueed, and then the plating treatment was performed to produce a bead wire.

 The bead wires prepared in Example 1, Comparative Example 1, and Comparative Example 2 were subjected to a tensile test, and the tensile strength (N / mm 2), the disconnection state at the time of extension to the wire, and the disconnection state of the welded part were examined. . The results are as described in Table 1 above.

As is apparent from Table 1, according to the manufacturing method of Comparative Example 1, although a wire rod having sufficient tensile strength (2200 N / mm 2) can be obtained, a high carbon steel having a large carbon content of 5.5 mm wire diameter can be obtained by one step. Reduction by high processing up to 1.2 mm in wire diameter prevents smooth elongation, which results in the disconnection of wires at the time of elongation to the wire, and high carbon content. The change in the structure of the heated portion was remarkable, and the number of disconnection of the welding point also occurred a lot.

Moreover, according to the manufacturing method of the comparative example 2, since the reduction rate (processing amount) by elongation with respect to a wire | line is small compared with the comparative example 1, the disconnection at the time of elongation with respect to a line does not generate | occur | produce, and the tensile strength is 1950 N / Although there is no problem in mm <2>, since carbon content is high, the structure change of the part heated at high temperature at the time of welding was remarkable similarly to the comparative example 1, and it resulted in the disconnection generate | occur | producing in a welding location.

In addition, since a carbon steel wire rod having a special wire diameter (4.5 mm) is required, in order to obtain a carbon steel wire rod having a wire diameter of 4.5 mm from the company, the general purpose (wire diameter of 5.5 to 6.5 mm) purchased from a steel maker is required. If a facility for patterning a carbon steel wire rod is required and the company does not have a facility, there is a restriction that an expensive busbar must be obtained from a steel maker.

In contrast, in Example 1 described above, since a hard steel wire having a carbon content of 0.63% by weight is used, for example, in order to extend the line from the wire diameter of 4.5 mm φ of Comparative Example 2 to the wire diameter of 1.20 mm φ , On the contrary, the amount of work is increased, but the carbon content is low and the material is soft, so that the gap between the ferrite and cementite is narrow and the structure is fine and smooth. Since no disconnection in was generated, it was possible to easily obtain a wire rod having a desired wire diameter by one wire extension, and a tensile strength (2000 N / mm 2) was also as desired as in Comparative Example 2.

In the disconnection test of the bus bar welding section, 11 busbars each having a length of about 1 m were prepared for Example 1, Comparative Example 1, and Comparative Example 2, and the welding procedure was performed for each of Example 1, Comparative Example 1, and Comparative Example 2. The welding, annealing, and deburring are repeated, followed by welding and joining to one wire. In addition, the wire welded to 10 places is stretched in a conventional manner to 1.20 mm ? The number of disconnections was measured. The results are as described in Table 1 above.

The photograph of FIG. 3 enlarges and shows the surface of the bead wire in the state which peeled off the plating layer of the surface of the bead wire manufactured as shown in FIG. The bead wires have an effect on the anchoring effect in adhesion with rubber according to the groove spacing of wrinkles (concave-convex) caused by the increase in the surface area due to the reduction of the diameter due to elongation to the wire. The surface of the bead wire prepared by Example 1, (B) is the surface of the bead wire prepared by Comparative Example 1, (C) is the surface of the bead wire prepared by Comparative Example 2 Are shown respectively. As a result of performing an adhesion test before and after aging of these bead wires, in Example 1, in both the initial adhesiveness before aging and the water-resistant adhesiveness which assumed the tire which ran after aging, the comparative example Better results than those of 1 and Comparative Example 2 were obtained. On the other hand, especially in the comparative example 2, the result was inferior to water-resistant adhesiveness. From this, in Example 1 and the comparative example 1, compared with the comparative example 2, it was proved that it was the groove space which was excellent in the anchoring effect.

And the test of the adhesive force was implemented based on the rubber adhesion test method prescribed | regulated to JISG3510. As the embedding rubber, the following compounding rubber was used as the bead insulation. The numerical values represent parts by mass. Natural rubber 50, SBR 50, carbon black 100 (cisting SO, Tokai Carbon Co., Ltd.) softener 25, calcium carbonate 25, talc 10, stearic acid 2, zinc oxide 5, sulfur 8, vulcanization Iii) Accelerator 1.

The embedding length of the bead wire in the rubber is 50 mm and the drawing speed is 150 mm / min, and the pulling force, that is, the adhesive force (N) and the adhesion rate (%) of the rubber remaining on the bead wire, is visually observed. It judged by. And as a bead wire, what plated Cu / Sn = 93/7 on the surface was used.

Here, the initial adhesive vulcanization conditions were performed at 150 degreeC x 40 minutes, and also the water-resistant adhesiveness was evaluated by said drawing adhesion test after leaving the vulcanized sample for 1 week in 70 degreeC * 95% RH atmosphere. Water resistance adhesive assumed the thermal deterioration conditions after tire running.

In the above embodiment, the wire diameter is 5.5 mm φ , the chemical component is C: 0.63%, Si: 0.21%, Mn: 0.52%, the remainder of the hard steel wire rod of Fe and unavoidable impurities, the true strain of 2.0 ~ in the range of 4.0, although the wire diameter 1.20mm φ 1 meeting described with respect to a reduction for example a line to the working height, the wire diameter of 6.5 mm φ, chemical composition, C: 0.63%, Si: 0.21%, Mn: 0.52% Even if the remainder was reduced by one line stretching to a wire diameter of 1.55 mm phi with Fe and unavoidable impurities, almost the same effect as in Example 1 described above can be obtained.

According to the bead wire of the above-described embodiment, a true strain rate of 2.0% by weight of carbon steel wire containing 0.61% or more and 0.65% or less, and a diameter of 5.5 mm to 6.5 mm by stretching treatment for one line In the range of ˜4.0, since the line is stretched to a predetermined final stretched wire diameter and has a pearlite structure in which the gap between ferrite and cementite is narrowed, the tensile strength is excellent while using a carbon steel wire having a general wire diameter. In addition, it is possible to obtain a useful bead wire for tires that has good adhesion to the surrounding rubber of the bead wire and does not cause disconnection at the time of extension to the wire and disconnection at the welding location. In particular, by extending the carbon steel having a low carbon content with a high reduction ratio, a bead wire having a narrow spacing between ferrite Fe and cementite Fe 3 C, and a fine structure and a smooth pearlite structure can be realized.

Moreover, according to the manufacturing method of the bead wire of above-mentioned embodiment, the carbon steel wire of 5.5 mm-6.5 mm in diameter containing carbon as weight% and 0.61% or more and 0.65% or less is the range of true strain 2.0-4.0 Since the wire is stretched by a process up to a predetermined final stretch wire diameter, it is possible to perform stretching of the wire with a high reduction ratio on a carbon steel wire having a relatively low carbon content without performing a patterning process. The carbon steel wire rod having a wire diameter (5.5 to 6.5 mm in diameter) can be stretched by a step up to the final elongation wire diameter suitable for the bead wire while not breaking the wire and securing the required tensile strength.

As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the structure demonstrated by embodiment, Comprising: The various forms are acquired within the range which does not deviate from the well-known of this invention described in the claim. will be.

[Industry availability]

The bead wire for tires which concerns on this invention, and its manufacturing method are suitable for obtaining the bead wire used for producing the bead core which is a reinforcement material of automobile tires.

11: descaling step,
12: coating liquid adhesion treatment step,
13: line elongation processing stage,
21: bluing process step,
22: plating process step

Claims (5)

 A carbon steel wire rod containing from 0.61% to 0.65% by weight, and having a diameter of 5.5 mm to 6.5 mm, has a true strain of 2.0 to 6.5 by stretching treatment for one wire. A bead wire for tires having a pearlite structure in which a line is stretched to a diameter of a predetermined final stretched wire in a range of 4.0, and the gap between ferrite and cementite is narrowed. The method of claim 1,
The bead wire for tires by which the line | wire is extended | stretched by 0.94-1.30mm phi by the extension process with respect to one line | wire. A carbon steel wire having a diameter of 5.5 mm to 6.5 mm, containing carbon by weight in a range of 0.61% or more and 0.65% or less, is wired by a process in which a true strain line diameter reaches a predetermined final extension line diameter in the range of true strain rate of 2.0 to 4.0. Elongate,
The manufacturing method of the bead wire for tires which blues the wire rod after extending | stretching the said wire, and performs plating after that. The method of claim 3,
The manufacturing method of the bead wire for tires which extended the wire | line with the diameter of 5.5 mm in carbon steel wire to the final extension wire diameter of 0.94-1.30 mm ( phi) . The method of claim 3,
The manufacturing method of the bead wire for tires which extended the line | wire to the final extension wire diameter of 1.5-2.20 mm ( phi) of the carbon steel wire rod of 6.5 mm in diameter.

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