C87500 Bare Copper Wire

Introduction

C87500 copper wire is a silicon-bronze alloy wire based on copper, containing approximately 3.5–4.5% silicon along with small amounts of other elements. This material is lead-free, meeting modern environmental regulations, while offering high strength and excellent elasticity, with tensile strength reaching over 400 MPa through cold working. Additionally, it exhibits outstanding corrosion resistance in atmospheric, fresh water, and marine environments, and provides good electrical and thermal conductivity, making it suitable for components that serve both electrical and structural functions.

In terms of processing and applications, C87500 copper wire demonstrates exceptional formability in both hot and cold working, allowing for easy bending, stamping, and drawing to meet the manufacturing requirements of complex-shaped parts. It also supports multiple joining methods, including soldering, brazing, and resistance welding, ensuring strong and reliable connections. As a result, it is widely used in automotive wiring terminals, electrical connectors, spring contacts, and various industrial fasteners and fittings.

parameter

C87500 Bare Copper Wire

Property	Typical Value / Range
UNS Number	C87500
Form	Bare Wire / Rod (Cold-drawn, custom order)
Diameter Range	0.5 mm – 12 mm (depending on supplier)
Temper Options	Annealed (Soft), ½ Hard, Hard
Tensile Strength (Annealed)	~380–420 MPa
Tensile Strength (Hard)	500–600 MPa (achieved by cold working)
Elongation (Annealed)	25–40%
Elongation (Hard)	5–15%
Electrical Conductivity	~6–7% IACS
Surface Finish	Bright, pickled, or coated as required
Lead-Free	Yes, RoHS & REACH compliant
Formability	Excellent for bending, stamping, and cold heading
Weldability	Good for resistance welding; soldering/brazing recommended
Typical Applications	Automotive wiring terminals, electrical connectors, spring contacts, fasteners

Advantages

Advantages of C87500 Bare Copper Wire

High Strength & Superior Elasticity

Through cold working, C87500 wire achieves a tensile strength of up to 500–600 MPa, significantly higher than many standard copper alloys. This high strength is complemented by excellent elastic recovery and wear resistance, enabling the wire to maintain consistent contact pressure over extended service life. These properties make it particularly suitable for spring contacts, terminal pins, and connectors that are subject to repeated mechanical stress and require long-term dimensional stability.

Lead-Free & Fully Environmentally Compliant

With a lead content consistently below 0.05%, C87500 wire fully complies with all major global environmental directives, including RoHS and REACH. This eliminates the health and safety risks associated with lead exposure during manufacturing, handling, and end-of-life recycling. As environmental regulations continue to tighten worldwide, choosing C87500 provides manufacturers with a future-proof material solution that avoids the need for costly material substitutions or compliance retrofits down the line.

Outstanding Corrosion Resistance Across Diverse Environments

The silicon-enriched matrix of C87500 forms a stable, protective oxide layer that delivers exceptional resistance to corrosion in a wide range of service conditions. Whether exposed to humid atmospheric conditions, fresh water, or full seawater immersion, this alloy consistently outperforms conventional copper alloys such as brass, phosphor bronze, and beryllium copper in terms of pitting, stress corrosion cracking, and general surface degradation. This makes it an ideal choice for marine hardware, offshore equipment, and industrial components operating in chemically aggressive environments.

Excellent Formability & Multiple Joining Options

C87500 wire exhibits outstanding ductility and workability in both hot and cold working processes, allowing for complex operations such as cold heading, bending, stamping, swaging, and drawing without compromising material integrity. This versatility enables the production of intricate part geometries with tight tolerances, reducing the need for secondary machining operations. Additionally, the wire supports a variety of reliable joining methods, including soldering, brazing, and resistance welding, providing engineers with flexible assembly options to suit different production requirements and cost targets.

Our case presentation

Applications for C87500 Bare Copper Wire

Automotive Electrical Systems

C87500 wire is widely used in automotive electrical systems, particularly in wire harness terminals, battery connectors, starter motor brushes, and sensor contacts. The alloy's high strength ensures reliable mechanical retention in crimped connections, while its excellent resistance to vibration fatigue and thermal cycling prevents loosening or failure over the vehicle's service life. Additionally, the lead-free composition meets stringent automotive industry standards such as IATF 16949 and global ELV (End-of-Life Vehicle) directives. Its corrosion resistance also makes it suitable for under-hood applications where exposure to heat, moisture, road salts, and chemical vapors is common, ensuring long-term electrical integrity in demanding environments.

Electrical Connectors & Terminals

In the broader electrical and electronics industry, C87500 wire is a preferred material for manufacturing high-reliability connectors, terminal blocks, relay contacts, and spring-loaded probes. The combination of good electrical conductivity (approximately 6–7% IACS) and exceptional mechanical strength allows engineers to design smaller, lighter connectors that carry comparable current loads without compromising durability. The wire's excellent spring properties ensure consistent contact force over repeated insertion and extraction cycles, which is critical for applications requiring high mating durability, such as industrial automation equipment, data center power distribution, and consumer electronics charging ports.

Industrial Fasteners & Hardware Components

C87500 wire is extensively used in the production of various industrial fasteners and hardware items, including rivets, screws, nuts, washers, clips, and pipe hangers. The alloy's superior corrosion resistance makes it particularly valuable in outdoor, marine, and chemical processing environments where carbon steel fasteners would quickly rust and stainless steel may suffer from chloride-induced pitting or galling during assembly. Its good cold-heading formability enables high-speed production of complex fastener geometries with tight dimensional tolerances, while its moderate hardness reduces tool wear during manufacturing. These fasteners are commonly found in shipbuilding, offshore oil and gas platforms, water treatment facilities, and architectural construction projects.

Precision Springs & Elastic Contact Elements

The exceptional elastic properties of C87500 wire, combined with its resistance to stress relaxation at elevated temperatures, make it an ideal material for precision coil springs, flat springs, Belleville washers, and elastomeric contact fingers. Unlike beryllium copper—which offers similar strength but poses significant health hazards during processing—C87500 provides a safer, more cost-effective alternative without sacrificing performance. These spring components are critical in applications such as electrical switchgear, circuit breakers, battery compartment contacts, EMI shielding gaskets, and test probe assemblies. The wire's ability to maintain consistent spring force over millions of cycles ensures reliable operation in safety-critical systems, including medical devices, aerospace instrumentation, and telecommunications infrastructure.

Strength

Company Strength

Our Team

Gnee steel group is a professional one-stop supply chain company for steel products in China. The copper technology has reached the world average technology level and has been approved by dozens of project companies to be the star company in Asia.

Established in 2008 with a registered capital of 5 million RMB, Gnai has made remarkable progress and development in the steel market. At present, the company has a total investment of 30 million yuan, a plant area of more than 35,000 square meters and more than 200 employees. With a clear strategic framework, a complete governance structure, a solid management foundation, and strong financial and human resources, the company is becoming the most professional internationalized steel supply chain company in the Central Plains.

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