3mm 6mm 8mm Grade 70 SAE1070 72A 72B 77B SWRH 82A 82B 2mm 3mm High Carbon Spring Steel Wire

Product Description:

Material Advantages:

American Standards (ASTM A29/A29M) Grade 70 (1070) and SAE 1070 refer to carbon steel with a carbon content of approximately 0.70%. Grade 70 and SAE 1070 are essentially the same material and are commonly used within the American Standard system.

Japanese/International Standards (JIS G 3502) SWRH 72A, SWRH 72B
SWRH 82A, SWRH 82B. "SWRH" stands for music wire/hard wire. A designates premium quality, while B designates standard quality (slightly higher in sulfur and phosphorus). The number (e.g., 72) is approximately equal to the carbon content multiplied by 100. For example, SWRH 72A/B has a carbon content of approximately 0.72%.

Chinese Standards (GB/T 4357) use similar grades but different designations (e.g., 72A, 82B). The Chinese designation system is similar to the Japanese SWRH system and can be interpreted in the same way. For example, the requirements for 72A are very similar to those for SWRH 72A.

Manufacturing Process:

1. Raw Material Preparation: Hot-rolled high-carbon steel wire rod with the aforementioned grade composition is used.
2. Surface Pretreatment: This includes mechanical rust removal (shot blasting), pickling to remove scale, followed by water washing, drying, and borax or phosphate coating to prepare for subsequent drawing.
3. Patenting: This is the most critical intermediate heat treatment step in producing high-strength, high-toughness steel wire. After being heated to the austenitizing temperature, the wire rod undergoes isothermal transformation in a 500-550°C molten lead bath (or modern, more environmentally friendly salt baths) to achieve a fine, strong, and tough sorbite structure.
4. Multiple Cold Drawing: The lead-quenched wire rod is gradually reduced to the target size (e.g., 3mm, 6mm) through multiple drawing stages. Each drawing step significantly increases strength and hardness, but also reduces ductility, necessitating intermediate heat treatment. 5. Intermediate Heat Treatment: If the wire becomes excessively hard between multiple drawing passes, low-temperature annealing is required to restore its plasticity for further processing.
6. Final Heat Treatment: If required, stress relief annealing (approximately 400°C) may be performed to eliminate processing stresses, stabilize dimensions, and improve coiling performance.
7. Surface Treatment and Coiling: The finished wire undergoes rust-proofing treatments such as galvanizing or bronze plating, or phosphating to enhance lubricity and corrosion resistance. Finally, it is coiled and packaged.

Features:

1. Extremely High Strength and Hardness: Through cold drawing, deformation strengthening, and heat treatment, this type of steel wire possesses exceptionally high tensile strength. For example, the tensile strength of SWRH 72B reaches approximately 1770-1960 MPa, while SWRH 82B even exceeds 2000 MPa, far exceeding that of ordinary steel.
2. Excellent Elasticity and Relaxation Resistance: With high elastic limit and yield strength, it can withstand large deformations and fully recover to its original shape. Its strong resistance to permanent deformation (relaxation) ensures that the spring maintains stable elastic force over long-term use.
3. Excellent Fatigue Life: The fine-grained troostite structure achieved through "lead bath quenching" provides excellent fatigue resistance, enabling it to withstand millions of cycles of repeated compression, torsion, or bending.
[Key Process] Lead bath quenching is the core step in achieving these high elasticity and fatigue life. 4. Precise and Consistent Dimensions: As finished cold-drawn products, their diameters (e.g., 2mm, 3mm, 6mm, 8mm) are precisely controlled with tight tolerances and a smooth, uniform surface, ensuring stability and consistency during subsequent coiling.
5. Versatile Processability: Depending on the final product's needs, various surface finishes (glossy, phosphated, galvanized, etc.) and heat treatments are available to optimize cold coiling performance, weldability, or corrosion resistance.

 

Standard:

 

Applications:

Spring Manufacturing Automotive seat springs, Simmons mattress springs, and torsion and tension springs for various mechanical equipment utilize their high elasticity and stress resistance. Common materials include 65#, 70#, 65Mn, 82B, 72A, and 72B.

Tools & Machinery: Various hand tools, machine tools, heavy machinery parts, and shafts require material strength and wear resistance. SAE 1070 steel, for example, is suitable for these applications.

Construction & Infrastructure: Prestressed concrete steel wire and wire rope, used in buildings, bridges, and other fields. High-carbon wire products such as SWRH77B/SWRH82B provide high-strength support.

High-end Industries: Marine engineering, oil extraction, nuclear power facilities, and more. These industries require extremely high material strength and durability. For example, SWRH77B/SWRH82B products have passed the international CARES certification.

 

 

Support and Services:

Professional Technical Team:

We have gathered the elites in the industry to form a professional technical team. The members have an average of more than 15 years of experience in the field of marine steel wire ropes. Facing the diverse needs of ship operations, whether it is the confusion in product selection or the special requirements for the performance of steel wire ropes under complex sea conditions, they can rely on their profound knowledge and rich experience to quickly provide accurate and professional solutions, facilitating the smooth progress of ship operations.

Comprehensive After-sales Service:

Since you choose our steel core galvanized high-carbon marine steel wire rope, our exclusive service will escort you throughout the whole process. We will establish a detailed product usage file and continuously track the product status. If there are any quality problems within the warranty period, we will respond promptly and provide free replacement and repair services. We will also conduct regular follow-up visits to collect your usage feedback, optimize the product performance, and provide 7×24-hour technical consultations to ensure your usage experience in all aspects.

 

 

 

Start your worry-free choice for your maritime business with our marine steel wire ropes. Our ropes feature advanced craftsmanship and excellent quality, capable of withstanding rigorous tests. Coupled with professional technical support and considerate after-sales service, we will provide solid guarantees for your business throughout the whole process.

 

Any question please let us know ,our JinCheng maritime will provide you the best service with 7*24 hours ~