Executive Summary
RF coaxial cables serve as the “blood vessels” of modern communication systems, undertaking the critical task of high-frequency signal transmission. The defining characteristic of their structure lies in the use of Copper-Clad Steel (CCS) as the inner conductor. Beyond this key distinction, the overall design remains consistent with conventional RF coaxial cables.
FISSOT leverages over 20 years of copper-clad steel technology expertise, employing advanced continuous cladding, welding, and drawing processes to deliver high-performance, cost-effective conductor solutions for communications, broadcasting, aerospace, and other industries. With the large-scale deployment of 5G networks and rapid data center construction, CCS inner conductors have become the industry mainstream choice.
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🔗 FISSOT Products:Copper-Clad Steel Wire
1. Structural Characteristics of Copper-Clad Steel Inner Conductors
1.1 Basic Structure
Copper-clad steel wire features a high-strength steel wire as the core, with a layer of oxygen-free copper bonded to its surface through metallurgical bonding, forming a composite conductor that combines the advantages of both metals.
The typical structure consists of three layers:
- Core: Low-carbon or high-carbon steel, providing mechanical strength and tensile properties
- Intermediate Layer: Copper-steel metallurgical bond layer, ensuring the copper layer and steel core do not separate
- Outer Layer: Oxygen-free copper (OFHC), providing excellent conductivity and high-frequency transmission performance
FISSOT employs a horizontal continuous casting cladding and welding process, achieving molecular-level bonding between the copper layer and steel core with a peel strength ≥15N/mm, far exceeding industry standards. This process ensures uniform copper layer and secure bonding, preventing delamination or cracking during subsequent drawing and bending operations.
🔗 Learn More:Copper-Clad Steel Wire Product Page
1.2 Performance Characteristics
CCS wire perfectly integrates the dual advantages of steel and copper, achieving optimal balance across electrical, mechanical, and economic dimensions.
| Steel Property Contributions | Copper Property Contributions |
| Tensile strength 350-760 MPa | Conductivity 21%-40% IACS optional |
| Operating temperature -40℃ to +150℃ | Low contact resistance, minimal signal reflection |
| Low thermal expansion coefficient, dimensional stability | High skin effect utilization at high frequencies |
| Creep resistance, no deformation under long-term load | Copper layer protects steel core from corrosion |
Comprehensive Advantages: High transmission efficiency (high-frequency performance matches pure copper), low material cost (30%-50% raw material reduction), high tensile strength (1-2× that of pure copper), lightweight (12%-13% density reduction), wear resistance, and excellent weldability.
🔗 Related Products:View CCS Wire Specifications
1.3 Product Classification
By Conductivity (IACS – International Annealed Copper Standard):
| Conductivity | Classification | Typical Applications |
| 21% IACS | Low conductivity | Grounding applications, lightning protection systems |
| 30% IACS | Medium conductivity | General RF cables, CATV distribution |
| 40% IACS | High conductivity | High-performance RF cables, 5G feeder cables |
By Mechanical Properties (Annealing State):
| State | Code | Tensile Strength | Elongation | Application Scenarios |
| Annealed (Soft) | A | 350-450 MPa | 20%-25% | Frequent movement, bending applications |
| Hard Drawn | HS | 550-650 MPa | 10%-15% | Fixed installation, general applications |
| Extra Hard Drawn | EHS | 700-760 MPa | 5%-8% | Overhead, long-span applications |
RF Cable Application Note: RF cables typically employ 30% or 40% IACS annealed (A) copper-clad steel as the inner conductor to balance conductivity and bending performance.
By Copper Layer Thickness: Standard type 0.254mm (indoor dry environments), Enhanced type 0.4mm (outdoor general environments), Anti-corrosion type 0.6-0.8mm (marine, chemical, and other high-corrosion environments).
🔗 Product Details:CCS Wire Copper Layer Options
2. Advantages of Copper-Clad Steel vs. Pure Copper Wire
2.1 Electrical Performance Comparison
| Parameter | Copper-Clad Steel | Pure Copper | Advantage Explanation |
| High-Frequency Attenuation (100MHz) | -2.1dB/100m | -2.3dB/100m | Skin effect concentrates current in copper layer |
| Transmission Efficiency | ≥98% | ≥96% | Copper layer purity up to 99.95% |
| Return Loss | ≥20dB | ≥18dB | Lower reflection |
| Characteristic Impedance | 50Ω±2Ω | 50Ω±3Ω | Better stability |
| VSWR | ≤1.2 | ≤1.3 | Superior signal integrity |
Technical Principle: At high frequencies (above 1MHz), the skin effect causes current to flow primarily on the conductor surface. At 100MHz, copper’s skin depth is approximately 6.6μm. Even with a copper layer of only 0.254mm (254μm), it is sufficient to carry all high-frequency current. Therefore, CCS delivers electrical performance nearly identical to pure copper in high-frequency applications, but at significantly lower cost.
DC Resistance Note: For DC or low-frequency (<1MHz) applications, CCS exhibits higher resistance than pure copper. For Φ1.0mm wire, CCS (30% IACS) DC resistance is approximately 0.07Ω/m, while pure copper is approximately 0.022Ω/m.
🔗 Technical Resource:CCS Performance Data
2.2 Mechanical Performance Comparison
| Material | Tensile Strength | Yield Strength | Elongation | Elastic Modulus |
| Pure Copper (Annealed) | 215-265 MPa | 70 MPa | 30%-40% | 110 GPa |
| CCS (Annealed) | 350-450 MPa | 280 MPa | 20%-25% | 140 GPa |
| CCS (Hard Drawn) | 550-650 MPa | 480 MPa | 10%-15% | 150 GPa |
| CCS (Extra Hard Drawn) | 700-760 MPa | 650 MPa | 5%-8% | 160 GPa |
Core Conclusion: For identical cross-sections and conditions, CCS wire delivers 1-2 times the mechanical strength of solid copper wire, with elastic modulus improved by approximately 30%-40%.
Bending Performance: CCS minimum bending radius is approximately 6× wire diameter (pure copper ≈4×), but repeated bending cycles ≥50 (pure copper ≥30), torsion cycles ≥20 (pure copper ≥15), demonstrating superior fatigue resistance.
2.3 Reliability and Service Life
CCS conductors have been validated through multiple accelerated aging tests, demonstrating excellent performance in demanding application scenarios.
| Test Item | Test Conditions | Test Results | vs. Pure Copper |
| Salt Spray Test | 5% NaCl, 48 hours | No corrosion | Equivalent |
| Damp Heat Test | 85℃/85%RH, 1000 hours | Stable performance | Equivalent |
| Temperature Cycling | -40℃↔+85℃, 500 cycles | No cracking | Superior |
| Vibration Test | 10-500Hz, 24 hours | No fracture | Superior |
Service Life Prediction:
- Indoor environments: ≥30 years
- Outdoor environments: ≥20 years (with protection)
- Marine environments: ≥15 years (tin-plated)
- Frequent movement scenarios: ≥50,000 bending cycles
Case Study: A communication base station using FISSOT CCS feeder cables was inspected after 12 years of operation, showing no significant electrical performance degradation and mechanical performance retention ≥95%.
🔗 Testing Information:CCS Testing Standards
2.4 Cost Advantages
Example: 1km Φ1.0mm Wire
| Cost Item | Pure Copper | CCS (30% IACS) | Savings |
| Raw Material Cost | ¥68,000 | ¥42,000 | 38% |
| Processing Cost | ¥5,000 | ¥6,000 | -20% |
| Total Cost | ¥73,000 | ¥48,000 | 34% |
Comprehensive Benefits:
- Finished cable cost reduced by 25%-35%
- Weight per unit length reduced by 12%-13%
- Transportation and installation costs reduced by 15%-20%
- Support structure pole count reduced by 10%-15%
FISSOT CCS helps customers reduce total costs by 30%-40%, significantly enhancing product market competitiveness.
2.5 Appearance and Assembly
Appearance Quality: FISSOT CCS wire features surface roughness Ra ≤0.8μm, roundness tolerance ≤0.01mm, copper layer uniformity deviation ≤3%, with no cracks, pores, inclusions, or other defects. Color, luster, and hand feel are indistinguishable from pure copper wire; end users cannot identify differences through visual inspection.
Assembly Convenience:
- Fine-diameter cables (below Φ0.5mm) gain necessary tensile strength, preventing installation breakage
- Moderate hardness, easy to cut, strip, and crimp, assembly efficiency improved by 20%
- Inner conductor rigidity superior to pure copper, easy insertion into connector interfaces with accurate alignment
Welding Performance: Suitable for tin soldering, silver soldering, laser welding, and exothermic welding; ultrasonic welding requires power parameter adjustment.
3. Application Areas
3.1 Communications Industry (Approx. 60%)
| Application Scenario | Recommended Specification | Core Advantages |
| 5G Base Station Feeders | 40% IACS Annealed | Low loss, high power capacity |
| 4G/LTE Antenna Feeders | 30%-40% IACS Annealed | Best cost-performance ratio |
| Microwave Relay Links | 40% IACS Hard Drawn | Stable high-frequency performance |
| Satellite Communication Ground Stations | 40% IACS Annealed | Low noise, high gain |
| CATV Coaxial Cables | 30% IACS Hard Drawn | Long-distance transmission, low cost |
| RF Jumpers | 40% IACS Annealed | Low insertion loss, high return loss |
🔗 Product Page:CCS Wire for RF Applications
3.2 Power Industry (Approx. 20%)
| Application Scenario | Recommended Specification | Core Advantages |
| High-Voltage Transmission Grounding | 21% IACS Hard Drawn | High strength, corrosion resistance |
| Substation Grounding Grids | 21% IACS Annealed | Easy installation, long service life |
| Lightning Protection Systems | 21%-30% IACS | Low impedance, lightning strike resistance |
| Power-Communication Composite Cables | 30% IACS | Integrated power + communication |
3.3 Electronics Industry (Approx. 10%)
| Application Scenario | Recommended Specification | Core Advantages |
| Aerospace Cables | 40% IACS Ultra-Light | Weight reduction, high reliability |
| Defense & Military Special Cables | Custom Specifications | Extreme environment adaptation |
| Automotive Wire Harnesses (High-Voltage) | 30% IACS Hard Drawn | Vibration resistance, long life |
| Rail Transit Signal Cables | 30% IACS | Electromagnetic interference resistance |
3.4 Other Applications (Approx. 10%)
Wide applications in test and measurement equipment, antenna feeder systems, RFID systems, IoT sensors, new energy (photovoltaic/wind power), and other fields.
4. FISSOT Product Series
4.1 Technical Specifications
| Parameter | Specification Range |
| Conductivity | 21% / 30% / 40% IACS (customizable) |
| Tensile Strength (Annealed) | 350-450 MPa |
| Tensile Strength (Hard Drawn) | 550-650 MPa |
| Tensile Strength (Extra Hard Drawn) | 700-760 MPa |
| Wire Diameter Range | 0.10mm – 5.0mm |
| Copper Layer Thickness | 0.254mm – 0.8mm (customizable) |
| Operating Temperature | -40℃ to +150℃ |
| Elongation (Annealed) | 20%-25% |
| Elongation (Hard Drawn) | 10%-15% |
| Density (30% IACS) | 7.8 g/cm³ |
🔗 Full Specifications:View Complete Product Specs
4.2 Quality Certifications
| Certification Type | Certification Standards |
| International Certifications | IEC 62561-2, UL 467, RoHS 2.0, REACH |
| Quality Management Systems | ISO 9001:2015, ISO 14001:2015, IATF 16949 |
| Industry Certifications | CE Marking, FCC Part 15, GR-487 |
4.3 Testing Capabilities
FISSOT is equipped with comprehensive testing laboratories to ensure quality for every production batch. Electrical performance testing uses micro-ohmmeters, eddy current conductivity meters, and vector network analyzers; mechanical performance testing uses universal material testing machines and wire bending testers; metallographic analysis uses metallographic microscopes, SEM, and eddy current thickness gauges; environmental testing uses salt spray chambers, constant temperature and humidity chambers, and high-low temperature shock chambers.
5. Comprehensive Advantage Comparison
| Comparison Dimension | CCS Advantage | Pure Copper Baseline | Actual Benefits |
| High-Frequency Performance | Lower attenuation, higher efficiency | Baseline | Insertion loss reduced 5%-10% |
| Mechanical Strength | 1-2× pure copper | 215-265 MPa | 350-760 MPa |
| Reliability | Impact-resistant, fatigue-resistant, long life | General | Service life extended 30%-50% |
| Cost | Significantly lower material and production costs | Baseline | Cost reduced 30%-40% |
| Weight | 12-13% lighter than pure copper | 8.9 g/cm³ | 7.8 g/cm³ |
| Appearance | Indistinguishable from pure copper | Baseline | Visually indistinguishable |
| Assembly | Easy connector insertion | Softer | Efficiency improved 20% |
6. Why Choose FISSOT?
| Advantage Dimension | Detailed Description | Customer Value |
| Advanced Manufacturing Process | Horizontal continuous casting cladding + multi-pass drawing | Stable quality, consistent batches |
| Quality Consistency | Copper layer uniformity deviation <3% | Reduced production defect rate |
| Customization Capability | Conductivity, wire diameter, copper layer thickness customizable | Meets special requirements |
| Technical Support | 10-person professional engineering team | Reduced R&D costs |
| Global Compliance | IEC, UL, RoHS, REACH certified | Barrier-free access to global markets |
| Production Capacity | 500 tons/month, 2-4 week delivery | Stable supply chain |
| Cost Advantage | Scaled production + process optimization | Enhanced customer competitiveness |
Service Commitments:
- ✅ 24-hour response
- ✅ Free samples
- ✅ 2-year warranty with lifetime technical support
- ✅ Custom development of exclusive specifications
🔗 Get Started:Contact FISSOT for Samples
7. Selection Guide
7.1 RF Coaxial Cable Application Recommendations
| Application Type | Conductivity | State | Copper Layer Thickness | Typical Specifications |
| 5G Base Station Feeders | 40% IACS | Annealed (A) | 0.254mm | Φ1.0-3.0mm |
| 4G/LTE Feeders | 30%-40% IACS | Annealed (A) | 0.254mm | Φ0.8-2.5mm |
| Jumpers & Patch Cables | 40% IACS | Annealed (A) | 0.254mm | Φ0.5-1.5mm |
| Drop Cables | 30% IACS | Hard Drawn (HS) | 0.254mm | Φ0.6-1.2mm |
| Indoor Distribution Systems | 30% IACS | Annealed (A) | 0.254mm | Φ0.4-1.0mm |
| CATV Trunk Lines | 30% IACS | Hard Drawn (HS) | 0.4mm | Φ1.5-3.0mm |
| Microwave Communications | 40% IACS | Hard Drawn (HS) | 0.254mm | Φ0.3-1.0mm |
| Satellite Communications | 40% IACS | Annealed (A) | 0.4mm | Φ0.8-2.0mm |
🔗 Order Now:CCS Wire Product Page
7.2 Grounding System Application Recommendations
| Application Type | Conductivity | State | Copper Layer Thickness | Typical Specifications |
| Substation Grounding Grids | 21% IACS | Annealed (A) | 0.4mm | Φ2.0-8.0mm |
| Lightning Down Conductors | 21% IACS | Hard Drawn (HS) | 0.4mm | Φ3.0-10.0mm |
| Equipment Grounding Wires | 30% IACS | Annealed (A) | 0.254mm | Φ1.0-4.0mm |
| Offshore Platform Grounding | 21% IACS | Hard Drawn (HS) | 0.6-0.8mm | Φ4.0-12.0mm |
7.3 Selection Process
Step 1: Determine Application Frequency — For frequencies below 1MHz, select 40% IACS or pure copper; for frequencies above 1MHz, CCS is preferred.
Step 2: Assess Mechanical Strength Requirements — For high-strength requirements (overhead/long-span), select Hard Drawn or Extra Hard Drawn; for general requirements, select Annealed.
Step 3: Evaluate Environmental Conditions — For indoor environments, select standard copper layer 0.254mm; for outdoor environments, select enhanced copper layer 0.4mm; for marine/chemical environments, select anti-corrosion copper layer 0.6-0.8mm with tin plating.
Step 4: Consider Cost Budget — For optimal cost-performance, select 30% IACS; for performance priority, select 40% IACS.
🔗 Need Help?Contact Our Technical Team
8. Frequently Asked Questions (FAQ)
What is copper-clad steel (CCS)?
Copper-clad steel is a bimetallic conductor with a steel core surrounded by a copper layer, combining steel’s strength with copper’s conductivity.
Why use CCS instead of pure copper for RF cables?
CCS offers equivalent high-frequency performance at 30-40% lower cost, with 1-2× higher tensile strength and 12-13% weight reduction.
What conductivity levels are available?
FISSOT offers 21%, 30%, and 40% IACS conductivity options, with 30-40% IACS recommended for RF applications.
How long does CCS last in outdoor environments?
With proper protection, CCS conductors last 20+ years outdoors, 30+ years indoors, and 15+ years in marine environments (tin-plated).
Is CCS suitable for 5G applications?
Yes, 40% IACS annealed CCS is the preferred choice for 5G base station feeders due to low loss and high power capacity.
What certifications does FISSOT CCS have?
FISSOT products are certified to IEC 62561-2, UL 467, RoHS 2.0, REACH, ISO 9001, ISO 14001, and IATF 16949 standards.
How do I request samples or get a quote?
Visit our Copper-Clad Steel Wire Product Page to contact our sales team. Free samples available with 3-5 business day delivery.