By Jianyun Cable – Professional Manufacturer of Reliable Electrical Cables

Steel wire armoured cable (SWA) is widely regarded as one of the most durable power cables available. However, no cable is perfect for every situation. Understanding the disadvantages of steel wire armoured cable helps engineers and installers make informed decisions in 2026 projects.

While SWA excels in mechanical protection, its drawbacks in weight, cost, and installation complexity can influence project planning. This guide examines these limitations honestly while maintaining a balanced view.

1. Introduction

Steel wire armoured cable provides excellent resistance to physical damage, making it popular for underground and industrial installations. Despite its strengths, several practical disadvantages can affect choice, budget, and long-term performance.

Recognising these limitations early allows better comparison with alternatives like unarmoured XLPE or aluminium wire armoured (AWA) cables. The key is matching the cable to the specific application requirements.

2. Heavy Weight and Handling Challenges

The primary disadvantage of steel wire armoured cable is its significant weight. Galvanized steel armour adds considerable mass compared to unarmoured equivalents.

Larger drums are required for transport, and manual handling becomes more difficult on site. This increases labour requirements and the need for mechanical lifting equipment.

In overhead or vertical installations, the weight can create additional stress on supports and glands, demanding stronger fixing methods.

3. Higher Purchase and Installation Cost

Steel wire armoured cable typically costs 30–50% more than comparable unarmoured cables due to the steel armour and additional manufacturing steps.

Installation expenses rise from specialist tools (SWA cutters, heavy-duty glands) and longer termination time. Overall project budgets can increase noticeably when extensive runs are needed.

Maintenance or future modifications also cost more because cutting and re-terminating SWA requires skilled labour and specific accessories.

4. Complex Installation and Termination

Terminating steel wire armoured cable demands precision. Incorrect armour earthing or poor gland installation can compromise safety and performance.

Specialist SWA glands and shrouds are essential, adding complexity compared to simple unarmoured cable joints. The process is time-consuming and requires training.

Bending radius is larger (typically 8–12 times overall diameter), limiting use in tight spaces or complex routing.

5. Corrosion Risks in Certain Environments

Although galvanized, steel armour can corrode in aggressive soils, coastal areas, or chemical exposure over time.

Corrosion weakens mechanical protection and may affect the armour's ability to serve as circuit protective conductor (CPC). Regular inspection becomes necessary in harsh conditions.

LSZH sheathed versions help, but corrosion remains a long-term consideration for buried steel wire armoured cable.

6. Reduced Flexibility and Bending Radius

The rigid steel armour reduces overall cable flexibility, making steel wire armoured cable unsuitable for frequent movement or vibrating machinery.

Tight bends risk damaging insulation or armour wires, leading to potential faults. This limitation restricts use in dynamic applications.

7. Magnetic Issues in Single-Core Applications

Steel armour is magnetic, causing eddy current heating in single-core AC circuits. This makes steel wire armoured cable unsuitable for single-core high-current installations.

Aluminium wire armoured (AWA) or non-metallic alternatives are preferred to avoid energy loss and overheating.

8. Alternatives to SWA Cable

Learn more in our blog post about What is Steel Wire Armoured Cable Used For?

9. When SWA is Still Worth It

Despite disadvantages, steel wire armoured cable remains the best choice where mechanical protection is critical: direct burial, outdoor exposure, industrial environments, and high-risk areas.

The trade-off between cost/weight and superior durability often favours SWA for long-term reliability and safety.

FAQ

Is steel wire armoured cable always the best choice?

No – it depends on the environment. For protected indoor runs, lighter unarmoured cables may be more practical and cost-effective.

Can corrosion affect SWA cable performance?

Yes, in aggressive soils or coastal areas. Proper bedding, warning tape, and periodic inspection help mitigate risks.

Why avoid single-core SWA in AC circuits?

Steel armour induces eddy currents and heating. Use AWA or non-metallic alternatives for single-core applications.