6mm Armoured Cable: A Complete Guide to Sizing, Uses & Installation

When choosing the right electrical cable for outdoor or underground wiring, the 6mm armoured cable is one of the most common and reliable options available. It’s tough, versatile, and built to handle demanding conditions, making it ideal for both domestic and commercial projects.

In this guide, we’ll explain exactly what a 6mm armoured cable is, what it’s used for, its current-carrying capacity, gland sizes, and installation best practices. You’ll also find answers to frequently asked questions about using this cable safely and effectively.

What Is a 6mm Armoured Cable?

A 6mm armoured cable is a type of electrical cable designed to provide mechanical protection and durability in challenging environments. The “6mm” refers to the cross-sectional area of the conductor inside the cable — not its overall width.

Armoured cables are made up of several layers:

• Conductors (usually copper or aluminium) that carry the electrical current
• Insulation to prevent electrical faults
• Armouring, which is a protective layer of steel or aluminium wires
• Outer sheath to protect against moisture, chemicals, and general wear

These layers work together to ensure safety and reliability in environments where standard electrical cables could be damaged or fail.

SWA vs AWA Cables

There are two main types of armoured cable:

• SWA (Steel Wired Armoured) – typically used for copper conductors and most domestic and commercial applications
• AWA (Aluminium Wired Armoured) – used for aluminium conductors, often in larger power distribution systems due to its lighter weight

Both provide excellent protection, but SWA is more common for 6mm cable sizes because copper conductors are standard in UK installations.

Why Use Armoured Cable?

Armoured cables are built for outdoor and underground installations, where extra protection is required. The steel or aluminium armouring acts as a shield against impact, crushing, and moisture ingress, ensuring long service life even in harsh conditions.

What Is 6mm Armoured Cable Used For?

The 6mm armoured cable is used in both domestic and industrial settings due to its balance between strength and flexibility.

Typical Domestic Uses

• Supplying power to garden offices, sheds, and workshops
• Running electricity to hot tubs, EV chargers, or outdoor sockets
• Wiring for outdoor lighting or garage circuits
• Connecting outbuildings to the main consumer unit

Its size makes it powerful enough for high-demand applications, yet manageable enough for small-scale installations.

Commercial and Industrial Uses

• Powering lighting systems, machinery, or heavy-duty tools
• Supplying electricity across construction sites or warehouses
• Use in car parks, street lighting, or temporary power distribution
  

In both cases, its steel wired armouring gives it an advantage in durability, making it safe for burial and resistant to accidental damage.

What Is the Diameter of 6mm Armoured Cable?

While the conductor size is 6mm², the overall diameter of the cable is larger due to the insulation, bedding, armour, and outer sheath.

On average, a 6mm 3-core SWA cable has an overall diameter of around 15mm to 18mm, depending on the manufacturer and construction type.

Typical Measurements

• Conductor cross-section: 6.0mm²
• Insulation thickness: 0.7mm (approx.)
• Overall cable diameter: 15–18mm
• Weight: roughly 0.8–1.1kg per metre

Understanding the diameter is crucial for choosing the correct glands, cleats, and conduits to ensure a secure and compliant installation.

How Many Amps Can 6mm Armoured Cable Take?

The ampacity (current-carrying capacity) of a 6mm armoured cable depends on several factors, including the installation method, temperature, and type of load.

Under normal conditions, a 6mm² copper SWA cable can safely carry between 34A and 47A for single-phase circuits, or higher for three-phase installations.

Approximate Amp Ratings

Voltage Drop Considerations

Voltage drop refers to the reduction in voltage as electrical current travels through the cable. Over long runs, this can affect performance.

For a 6mm cable, voltage drop is approximately 7.3 mV/A/m (millivolts per amp per metre). For long-distance installations, it’s important to calculate this to avoid underpowered equipment.

A simple rule of thumb:

Keep total voltage drop under 5% of your circuit voltage (11.5V for 230V systems).

If your cable run exceeds 50 metres, you may need to size up to 10mm or 16mm to maintain efficiency.

What Size Gland for 6mm SWA Armoured Cable?

Choosing the right gland size ensures a secure termination and maintains the integrity of the cable’s protection.

For 6mm SWA armoured cable, the typical gland size is 20mm (known as BW20 or CW20 depending on the type).

Types of Cable Glands

• BW glands – for indoor installations where the cable isn’t exposed to moisture
• CW glands – for outdoor use, offering weatherproof sealing

Installation Tips

• Always use the correct gland kit for the cable type and size
• Ensure the armour wires make good electrical contact with the gland body
• Use a shroud for additional weatherproofing outdoors

Batt Cables stocks a full range of BW and CW glands designed for compatibility with 6mm SWA cables.

SWA vs AWA: What’s the Difference?

Both SWA (Steel Wired Armoured) and AWA (Aluminium Wired Armoured) cables provide mechanical protection, but the materials differ in weight, conductivity, and application.

For most 6mm applications, SWA remains the preferred choice due to its robustness and compatibility with copper conductors.

Want to understand the difference between SWA and AWA in more detail? We’ve written a guide to explain the differences. Read the full SWA vs AWA guide here.

Installation Tips for 6mm Armoured Cable

Installing armoured cable requires care and compliance with wiring regulations. Here are key tips for safe and efficient setup:

Outdoor and Underground Installation

1. Plan the route: Avoid areas prone to digging or waterlogging.
2. Depth: Bury cables at a depth of at least 450mm in gardens or 600mm under driveways.
3. Use warning tape: Place electrical hazard tape above buried cables.
4. Protection: Use conduit or ducting in high-risk zones to prevent damage.

Fixing and Termination

• Use cable cleats to secure the cable at regular intervals (every 300–400mm).
• Ensure bedding and sheathing remain intact during installation.
• Use glands appropriate for your environment (BW or CW).

Testing and Compliance

• Always test insulation resistance and continuity after installation.
• Ensure compliance with BS 7671 (IET Wiring Regulations).
• If unsure, consult a qualified electrician before energising the circuit.

Choosing the Right 6mm Armoured Cable for Your Project

Selecting the correct 6mm armoured cable depends on several variables:

1. Voltage and Load Requirements – Check your equipment’s power rating and ensure the cable can handle it.
2. Distance and Voltage Drop – Longer runs may need a thicker cable to prevent loss.
3. Installation Method – Decide if it’ll be clipped, buried, or laid in conduit.
4. Environmental Conditions – Choose CW glands and UV-resistant sheaths for outdoor use.

Batt Cables provides a wide range of 6mm SWA and AWA cables, all manufactured to strict quality standards for reliable performance in every application.

Common FAQs About 6mm Armoured Cable

Can I use 6mm SWA cable for outdoor sockets?

Yes, 6mm SWA cable is ideal for outdoor sockets due to its armouring and weather resistance. Always ensure it’s correctly terminated and protected with a suitable gland and RCD device.

How far can I run 6mm armoured cable?

This depends on the load and acceptable voltage drop. For a 32A circuit, a 6mm SWA cable can typically run up to around 50 metres before voltage drop becomes significant. For longer distances, consider 10mm.

Is 6mm armoured cable suitable for EV chargers?

Yes, many EV charger installations use 6mm SWA cable, but always confirm with your charger’s specifications and consult an electrician to ensure compliance with IET Wiring Regulations.

How do I connect 6mm SWA cable to a consumer unit or junction box?

Use the correct gland kit for termination, ensuring the armour wires are earthed properly. Connect the live, neutral, and earth conductors securely within the unit.

Can I bury 6mm armoured cable directly underground?

Yes, it’s designed for direct burial. Ensure it’s laid at the correct depth, on a sand bed, and covered with warning tape before backfilling.

What’s the difference between single-core and multicore 6mm SWA?

Single-core is used mainly in industrial power distribution; multicore (such as 2-core or 3-core) is more common in domestic setups.

Where to Buy 6mm Armoured Cable in the UK

Batt Cables is one of the UK’s leading suppliers of 6mm armoured cable, trusted by trade professionals and contractors across multiple industries.

We stock a wide range of SWA and AWA cables, available in various core configurations and lengths. Each cable is manufactured to British Standards (BS5467), ensuring top-quality performance and safety.

If you’re planning an outdoor, underground, or high-load installation, our experts can help you choose the best option for your project.

For a deeper understanding of different armoured cable types, ratings, and installation guidance, visit our full resource:
Armoured Cables: The Complete Guide

How to Accurately Size Your Cable with the 6mm Armoured Cable Calculator

Before starting any installation, it’s crucial to ensure your chosen cable size is suitable for the intended load and distance. Even though 6mm armoured cable is one of the most popular and versatile options, its performance can vary depending on installation conditions, voltage drop, and current demand. That’s why Batt Cables offers an easy-to-use 6mm armoured cable calculator designed to help you make accurate sizing decisions in minutes.

Our calculator takes into account essential variables such as cable length, load (in amps or kilowatts), and installation method to provide an instant recommendation. Whether you’re powering an EV charger, outdoor lighting, or machinery, the 6mm armoured cable calculator ensures your setup meets current regulations and operates efficiently. It also helps you avoid common issues like excessive voltage drop or overheating, both of which can lead to reduced performance or premature wear.

For electricians and contractors, using this tool saves valuable time during planning and quoting, while homeowners can gain confidence that their installation is both safe and compliant. Simply input your project details, and the calculator will suggest the most appropriate armoured cable size and type, including 6mm, 10mm, or 16mm options where applicable.

By combining professional-grade products with expert tools like our armoured cable calculator, Batt Cables makes it easier than ever to design and install electrical systems that deliver performance, safety, and reliability.

Cables by Industry: Choosing the Right Solution for Every Sector

Every industry has unique requirements when it comes to electrical installations. From demanding environments to strict safety standards, choosing the right cable type ensures long-term reliability, performance, and compliance. At Batt Cables, we recognise that each project is different — which is why we offer a complete selection of cables by industry designed to meet the specific needs of every sector.

Whether you’re managing a construction project, operating within industrial automation, or developing a renewable energy site, the correct cable selection can make all the difference. For instance, marine-grade armoured cables are engineered for offshore and shipboard applications, providing corrosion resistance and mechanical protection against movement and vibration. Meanwhile, construction cables used in building services often prioritise LSZH (Low Smoke Zero Halogen) performance, flexibility, and compliance with BS and IEC standards for safety in public spaces.

Our specialist cable categories include:

• Construction and Building Services Cables – LSZH, power, and control cables for commercial and residential installations.
• Utilities and Renewable Energy Cables – robust underground and high-voltage cables ideal for solar, wind, and power distribution networks.
• Oil, Gas, and Petrochemical Cables – flame-retardant, hydrocarbon-resistant cables built for safety in hazardous zones.
• Marine and Offshore Cables – salt-resistant and pressure-tested cables that meet international marine standards.
• Transportation and Rail Cables – durable, low-smoke power and signalling cables for road, rail, and tunnel environments.
• Industrial Automation and Data Cables – precision-engineered cables for control systems, instrumentation, and data transmission.

By selecting industry-specific cables, you can improve safety, reduce downtime, and ensure your installation meets both performance and regulatory requirements. Explore Batt Cables’ full range of cables by industry to find the perfect solution — whether you need construction cables, marine-grade armoured cables, or industrial cables built to perform in the toughest conditions.

Key Takeaway

A 6mm armoured cable offers a strong, dependable solution for wiring projects that demand protection and performance. From powering outbuildings and EV chargers to industrial systems, it delivers durability and safety when installed correctly.With quality materials and compliant construction, Batt Cables ensures every armoured cable meets the standards professionals expect.