Oct 30, 2025
Is CCS Really Stronger Than Copper?
Introduction
For decades, Copper Clad Steel (CCS) conductors have been trusted for applications where both mechanical strength and electrical performance are essential — especially in grounding and overhead power systems. By combining steel’s tensile strength with copper’s high conductivity, CCS has become a preferred solution for projects exposed to vibration, bending, or long-term stress.Still, many engineers and buyers ask the same question: Is CCS really stronger and more durable than pure copper conductors?
To find out, we conducted comparative tests on TDDL bare conductors, following a bending fatigue model that better represents real-world mechanical stress than traditional single-pull tests.
The Challenge
Typical tensile tests measure how much load a conductor can handle before a single, static break. But that doesn’t reflect what happens in service.In actual installations, conductors are exposed to repeated bending, vibration, wind load, and movement — forces that cause fatigue over time rather than sudden failure.
To answer this challenge, we designed a test to directly compare TDDL CCS conductors with equal-capacity copper conductors, under repeated mechanical stress, and find out which material truly lasts longer.
Flex Fatigue Testing
Instead of measuring one-time break strength, this test focuses on how many bending cycles a conductor can endure before failure.Each sample was bent 90° left and 90° right — one complete cycle — until visible or audible signs of fracture appeared.
To ensure accuracy, especially with multi-strand conductors, we used acoustic monitoring to detect the instant a single strand fractured. This prevents under-reporting fatigue damage that might occur before the conductor stops working entirely.
This method gives a fairer comparison between multi-strand CCS and solid or stranded copper wires, since it captures early fatigue behavior rather than waiting for full electrical failure.
Our Test
We selected several specifications of TDDL Copper Clad Steel bare conductors — including 19 × No. 5, 19 × No. 6, and 7 × No. 4 constructions — as listed on our product page.Each sample was cut to equal length, stripped at both ends, and mounted on a cyclic bending tester. Every cycle consisted of a left-right 180° motion, repeated until the first audible strand break or full conductor failure occurred.
For comparison, we prepared copper conductors with equal ampacity and similar cross-section.
All tests were conducted under consistent ambient temperature and tension to maintain repeatability.
Test Results
Across multiple conductor sizes, TDDL CCS conductors showed much better flex-fatigue endurance than copper ones.While precise fatigue-cycle counts vary by construction, the average endurance ratio ranged from 2× to 5× longer life than equivalent copper conductors.
For reference, here’s some mechanical data from our CCS (40%IACS) product line:
| Construction | Cross Section (mm²) | Min. Breaking Load (kN) | Max. DC Resistance (Ω/km) |
| 19 × No. 5 | 318.71 | 216.66 | 0.14423 |
| 19 × No. 6 | 252.71 | 179.45 | 0.18183 |
| 7 × No. 4 | 148.06 | 96.15 | 0.30930 |
The results confirm that CCS conductors offer not only high static strength but also superior resistance to fatigue and vibration, which is crucial for long-term reliability in grounding and overhead systems.
Conclusion
With a refined bending fatigue test with acoustic monitoring, we verified that TDDL Copper Clad Steel conductors can withstand much more mechanical stress than pure copper conductors of the same ampacity.This advantage translates into longer service life, reduced maintenance, and safer performance in demanding environments — are used in place of copper conductors in grounding applications and systems. In such CCS cases, when both conductivity and durability matter, CCS delivers the balance modern electrical networks need.
In short, when both conductivity and durability matter, CCS delivers the balance modern electrical networks need.
