SWA vs SWB Cable: Steel Wire Armour and Steel Wire Braid Explained

Choosing between SWA vs SWB cable requires understanding how two different steel protection systems affect mechanical strength, flexibility, cable diameter, installation and the type of physical stress a cable can tolerate. Both Steel Wire Armour and Steel Wire Braid can provide additional mechanical protection, but they are constructed differently and should not be treated as interchangeable.

SWA uses galvanized steel wires applied around the cable in a helical armour layer. This construction is typically selected where strong resistance to crushing, impact and substantial mechanical stress is required. SWB uses finer steel wires woven into a braided layer, allowing the cable to retain greater flexibility while still receiving additional mechanical protection.

The distinction is relevant to instrumentation cables, signal and control cables, industrial Ethernet cables and certain fiber optic cable constructions. A fixed underground or heavy industrial route may favour SWA, while an installation involving tighter routing, vibration or a greater need for flexibility may benefit from SWB.

Quick answer: Choose SWA when maximum mechanical robustness is the priority, particularly for fixed and heavily exposed installations. Choose SWB when the cable still requires mechanical reinforcement but flexibility, tighter routing or vibration tolerance is also important. The final decision should follow the actual cable design, route and project specification rather than the armour acronym alone.

SWA vs SWB Cable at a Glance

Characteristic	SWA	SWB
Full name	Steel Wire Armour	Steel Wire Braid
Construction	Galvanized steel wires helically applied around cable	Fine steel wires interwoven into braided layer
Primary function	Heavy mechanical protection	Mechanical protection with greater flexibility
Crush resistance	Generally higher	Moderate to high depending on design
Tensile reinforcement	Generally stronger	Good, but usually lower than comparable SWA
Flexibility	Lower	Higher
Weight	Generally higher	Generally lower
Tight routing	More demanding	Often easier
Typical use	Fixed, underground and heavy industrial routes	Industrial routes requiring protection plus flexibility

The table describes the general engineering difference, but actual performance depends on steel-wire diameter, coverage, cable diameter, sheath materials and the complete product construction.

Therefore, SWA should not automatically be described as “strong” and SWB as “weak.” Both can provide significant protection when properly designed for their intended applications.

What Is SWA Cable?

SWA means Steel Wire Armour.

In an SWA cable, galvanized steel wires are applied helically around an inner sheath or bedding layer. An outer sheath is then typically extruded over the armour.

A simplified SWA cable construction can therefore contain:

• Conductors, signal pairs or optical elements
• Insulation
• Screening where required
• Inner sheath or bedding
• Galvanized steel wire armour
• Outer sheath

The steel wires provide a strong protective structure around the functional cable core.

What Is the Main Purpose of SWA?

SWA primarily protects the cable against substantial mechanical stress.

Depending on the cable design and installation, it can improve resistance to:

• Crushing forces
• Impact
• Accidental mechanical damage
• Rodent attack
• Tensile stress
• Installation damage
• External physical loading

This makes SWA particularly useful in heavy industrial and infrastructure applications.

Where Is SWA Commonly Used?

SWA constructions can be considered for:

• Oil and gas facilities
• Refineries
• Petrochemical plants
• Power plants
• Mining projects
• Tunnels
• Heavy industrial facilities
• Outdoor process areas
• Underground infrastructure
• Mechanically exposed cable routes

However, the presence of SWA alone does not automatically mean that a cable is suitable for every underground or direct-burial application.

Water protection, sheath material, chemical exposure and environmental requirements must still be verified separately.

What Is SWB Cable?

SWB means Steel Wire Braid.

Instead of applying comparatively larger steel wires helically around the cable, SWB uses fine steel wires interwoven into a braided structure.

This braided geometry allows the protective layer to adapt more easily as the cable bends.

As a result, SWB can provide a useful compromise between:

• Mechanical protection
• Abrasion resistance
• Flexibility
• Routing efficiency
• Reduced cable weight

What Is the Main Purpose of SWB?

SWB primarily provides mechanical reinforcement while allowing more flexibility than a typical SWA construction.

This can make steel wire braid useful where a cable:

• Must pass around tighter bends
• Is routed through complex trays
• Experiences vibration
• Requires abrasion protection
• Needs moderate mechanical reinforcement
• Would become unnecessarily heavy or rigid with SWA

Does SWB Mean the Cable Is Suitable for Continuous Movement?

Not automatically.

This is an important distinction.

SWB can make an armored cable more flexible than an equivalent SWA design, but this does not automatically make it a continuous-flex or robotic cable.

Applications involving millions of bending cycles, drag chains, robotics or continuous torsional movement require the complete cable construction to be designed and tested for dynamic operation.

A standard SWB cable should therefore not be specified for continuous movement solely because steel braid is more flexible than steel wire armour.

SWA vs SWB Cable: What Is the Main Difference?

The central difference between SWA vs SWB cable is the geometry of the protective steel layer.

SWA: steel wires run helically around the cable.

SWB: finer steel wires cross over one another to form a braid.

This structural difference changes how the finished cable behaves mechanically.

Engineering Requirement	SWA	SWB
Maximum mechanical robustness	Strong advantage	Good but generally lower
Crush protection	Generally stronger	Moderate to strong depending on construction
Tensile reinforcement	Generally stronger	Good
Flexibility	Lower	Higher
Tight bends	More difficult	Generally easier
Vibration	Suitable depending on complete cable	Can be advantageous where greater flexibility is required
Weight	Generally higher	Can be lower
Fixed heavy-duty installation	Often preferred	Possible where protection requirement is moderate

SWA vs SWB: Which Provides Better Mechanical Protection?

For comparable cable designs, SWA is generally selected when the highest level of mechanical protection is required.

The helically applied steel wires create a substantial protective structure around the cable.

This makes SWA particularly effective where crushing, impact or strong external mechanical loads are credible risks.

SWB still provides meaningful mechanical protection, but its main advantage is that it achieves reinforcement with a more flexible architecture.

The decision can therefore be summarized as:

SWA prioritizes mechanical robustness.

SWB balances protection with flexibility.

However, project engineers should compare actual mechanical datasheets whenever possible rather than relying solely on the armour abbreviation.

SWA vs SWB: Which Is More Flexible?

SWB generally provides greater flexibility.

The interwoven steel wires can move relative to one another as the cable bends. This allows the armour layer to conform more easily to changes in cable geometry.

By contrast, the larger steel wires used in an SWA construction add stiffness to the cable.

Greater flexibility can be particularly useful in:

• Industrial cable trays
• Confined routes
• Complex machinery layouts
• Offshore installations
• Control and instrumentation systems
• Areas containing repeated changes in direction

This does not mean the SWB cable can ignore its specified minimum bending radius.

Installers must always follow the manufacturer’s technical data.

SWA vs SWB: Which Is Better for Underground Installation?

SWA is commonly preferred for heavy-duty fixed underground applications because of its strong mechanical protection.

However, underground installation involves more than armour.

The cable may also face:

• Water ingress
• Soil pressure
• Rodents
• Stone impact
• Ground movement
• Chemical contamination
• Pulling forces

Therefore, an SWA layer should be evaluated together with:

• Outer sheath material
• Water-blocking design
• Operating temperature
• Required installation method
• Manufacturer approval for direct burial or underground use

An SWB cable can also be used in underground or demanding environments when its complete construction has been designed for that application.

The correct conclusion is therefore not that “SWA means underground and SWB means indoor.”

SWA is simply more commonly selected where underground mechanical loads are especially demanding.

SWA vs SWB for Oil and Gas Projects

Oil and gas projects can legitimately use both armour types.

For example, a refinery may contain:

• Underground instrument routes
• Outdoor pipe racks
• Control buildings
• Process units
• Equipment skids
• High-vibration machinery
• Confined cable trays

A fixed route facing strong mechanical exposure may justify SWA.

Meanwhile, an installation requiring greater routing flexibility while still needing mechanical reinforcement may favour SWB.

The project specification should therefore evaluate:

• Mechanical stress
• Route geometry
• Vibration
• Rodent exposure
• Installation method
• Required sheath material
• Fire requirements
• Grounding requirements

There is no universal rule stating that every oil and gas cable must use SWA.

SWA vs SWB for Instrumentation Cables

Instrumentation cables carry sensitive analogue and digital process signals, so armour selection should remain separate from signal-screen selection.

An armored instrumentation cable can contain:

• Twisted pairs or triads
• Individual screens
• Overall screen
• Drain or earth wires
• Inner sheath
• SWA or SWB mechanical protection
• Outer sheath

The instrumentation screens primarily address electromagnetic interference.

The steel armour primarily addresses mechanical protection.

When Is SWA Suitable for Instrumentation Cable?

SWA can be appropriate where instrumentation cables pass through:

• Heavy process areas
• Underground routes
• High-impact environments
• Rodent-prone areas
• Exposed industrial infrastructure

When Is SWB Suitable for Instrumentation Cable?

SWB can be attractive where instrumentation cables require:

• Mechanical reinforcement
• Greater installation flexibility
• Tighter routing
• Resistance to abrasion
• Improved handling in complex industrial layouts

The electrical signal architecture can remain essentially the same while the armour changes according to mechanical requirements.

SWA vs SWB for Ethernet Cable

Industrial Ethernet cables can also use either steel wire armour or steel wire braid.

ETK Kablo offers armored constructions across Cat5e, Cat6 and Cat6A product families.

For example, an industrial Cat6A cable can retain its required twisted-pair geometry and Ethernet screening while an additional SWA or SWB layer provides mechanical protection.

SWA can be suitable for:

• Fixed industrial LAN routes
• Outdoor infrastructure
• Underground LAN links
• High mechanical-risk environments

SWB can be considered where:

• The route contains tighter bends
• Cable handling flexibility is important
• Mechanical reinforcement is still required
• The cable passes through complex industrial tray systems

Does SWA or SWB Increase Ethernet Speed?

No.

Armour does not determine Ethernet category or bandwidth.

A Cat6A cable remains Cat6A because its electrical construction meets the applicable Category 6A transmission requirements.

The armour is added to protect that transmission structure from physical damage.

SWA vs SWB for Fiber Optic Cables

Fiber optic cables can also use SWA or SWB where high levels of mechanical reinforcement are required.

Since optical fibers transmit light rather than electrical current, the armour does not improve optical bandwidth.

Instead, it protects components such as:

• Loose tubes
• Optical fibers
• Strength members
• Water-blocking materials
• Inner sheaths

SWA can provide heavy mechanical protection for demanding fixed fiber routes.

SWB can provide reinforcement where additional flexibility is beneficial.

Fiber projects can also use other armour systems such as corrugated steel tape or non-metallic reinforcement, so SWA and SWB should not be viewed as the only possible mechanical-protection options.

Does SWB Provide Better EMI Shielding Than SWA?

A metallic braid can influence electromagnetic behaviour because its interwoven metallic structure surrounds the cable core.

However, this point should be treated carefully in signal and data cable specifications.

SWB should not automatically replace a dedicated electromagnetic screen.

For example, an instrumentation cable may use:

• Al/PET foil around pairs
• Overall Al/PET foil
• Tinned-copper braid
• Drain wires

These elements are specifically engineered to control electromagnetic interference and signal coupling.

A galvanized steel wire braid is primarily selected for mechanical protection.

Therefore, if EMI protection is important, engineers should specify the required electrical screen independently from SWA or SWB armour.

Does SWA Provide EMI Shielding?

Metallic steel armour can affect electromagnetic fields, but it should likewise not be treated as an automatic substitute for a dedicated foil or braid screen.

In screened instrumentation or Ethernet cables, the intended signal screen should remain clearly identified in the construction.

This prevents a common specification error:

Armour and shielding are not the same engineering function.

SWA vs SWB and Rodent Protection

Both steel constructions can provide a physical barrier against rodent attack.

SWA generally offers particularly robust protection because of the substantial steel wire layer.

SWB can also increase resistance to rodents compared with an unprotected cable.

However, rodent severity, braid coverage, wire dimensions and complete cable construction all matter.

Projects with a severe rodent requirement should therefore state that requirement explicitly rather than assuming any steel-containing cable automatically provides identical protection.

SWA vs SWB and Cable Weight

SWA typically adds more steel mass to the cable than a lighter braided protection system.

This can affect:

• Drum weight
• Shipping
• Manual handling
• Pulling tension
• Tray loading
• Support requirements
• Installation labour

SWB can provide an advantage where reducing cable weight is valuable while still retaining additional mechanical protection.

Actual weight should nevertheless be taken from the cable datasheet because construction differences can be significant.

SWA vs SWB and Cable Diameter

Armour construction can also affect overall cable diameter.

An SWA cable normally requires an inner sheath or bedding layer followed by steel wires and an outer sheath.

SWB can sometimes create a more compact protective construction because fine braided wires form a relatively conformable layer around the cable.

For large multi-pair instrumentation cables or high-density industrial Ethernet installations, this difference can influence:

• Tray fill
• Gland size
• Entry points
• Installation space
• Drum capacity

Again, engineers should compare actual dimensions rather than applying a universal assumption.

SWA vs SWB and Bending Radius

SWB generally offers an advantage where tighter cable routing is required.

However, neither armour system permits unlimited bending.

The minimum bending radius depends on the complete cable design, including:

• Conductor construction
• Insulation
• Number of cable elements
• Screening
• Inner sheath
• Armour
• Outer sheath

Therefore, the manufacturer’s specified bending radius remains the controlling value.

SWA vs SWB and Vibration

SWB can be attractive in environments involving vibration because the braided structure accommodates movement more readily than a comparatively rigid armour layer.

Examples can include:

• Machinery
• Equipment skids
• Industrial automation
• Offshore structures
• Process equipment

However, vibration resistance must still be evaluated as part of the complete cable design.

Steel wire braid alone does not automatically qualify a cable for every high-vibration or moving application.

SWA vs SWB and Cable Glands

The two armour constructions also influence termination.

SWA cables generally use glands designed to capture and terminate the steel wire armour correctly.

SWB constructions require compatible termination methods that secure the braid while maintaining the mechanical and, where applicable, bonding requirements of the system.

Project designers should therefore coordinate:

• Cable diameter
• Armour diameter
• Gland type
• Ingress protection
• Bonding arrangement
• Hazardous-area certification where applicable

Cable and gland selection should not be treated as separate decisions.

SWA vs SWB and Grounding

Both constructions contain metallic steel and can therefore introduce bonding or grounding considerations.

The required arrangement depends on:

• Cable application
• Electrical system
• Local regulations
• Equipment design
• Hazardous-area requirements
• Project grounding philosophy

This is particularly important where the cable enters metallic enclosures or equipment located in hazardous industrial areas.

The project engineer should define how metallic armour is terminated and bonded rather than relying on the cable manufacturer to determine the complete grounding philosophy.

Does SWA or SWB Mean the Cable Is Fire Resistant?

No.

SWA and SWB describe mechanical protection.

Fire performance remains a separate specification.

Either armour system can be combined with cable constructions using:

• PVC
• LSZH
• Flame-retardant materials
• Fire-resistant insulation systems
• Different CPR Euroclasses

An SWA or SWB designation therefore does not automatically prove:

• IEC 60332 performance
• FE180
• PH120
• E30
• E60
• E90
• LSZH performance

Does SWA or SWB Mean Direct Burial?

No.

This is another important procurement distinction.

Mechanical armour is only one part of underground cable design.

Direct burial can also require:

• Water resistance
• Moisture blocking
• Suitable outer sheath
• Crush resistance
• Rodent resistance
• Temperature capability
• Chemical resistance

The datasheet or project specification should explicitly confirm suitability for direct burial.

Which Should You Choose: SWA or SWB?

Project Requirement	Armour to Consider	Reason
Maximum mechanical protection	SWA	Robust steel wire structure
Heavy fixed industrial route	SWA	Strong protection against impact and crushing
Demanding underground route	SWA often preferred	Strong mechanical and tensile protection
Protected industrial route requiring additional reinforcement	SWB	Provides protection with greater flexibility
Confined or complex tray route	SWB	More flexible braided construction
Vibration is an important consideration	SWB may be advantageous	Braid accommodates movement more readily
Lowest possible weight is important	Compare SWB first	Can use less steel than heavy SWA designs
Severe rodent and impact exposure	SWA	Heavy steel armour provides strong physical barrier

The table provides general selection logic rather than a substitute for product-specific engineering data.

Common Mistakes When Comparing SWA and SWB Cable

1. Assuming SWA Is Always Better

SWA provides strong mechanical protection, but its additional weight and stiffness may be unnecessary where moderate protection and flexibility are more important.

2. Assuming SWB Is a Flexible Robotic Cable

SWB provides greater flexibility than typical SWA, but continuous-flex applications require a cable specifically engineered for repeated movement.

3. Treating SWB as an EMI Screen

Steel braid may influence electromagnetic performance, but signal and data cable screening should be specified separately using the appropriate foil or conductive screen construction.

4. Assuming SWA Automatically Means Direct Burial

The complete cable must be designed for the moisture, mechanical and environmental conditions of underground installation.

5. Assuming SWB Cannot Be Used Outdoors

Outdoor suitability depends primarily on the complete cable design and outer sheath rather than the armour geometry alone.

6. Ignoring Cable Diameter

Armour can significantly affect cable diameter, tray fill and gland selection.

7. Ignoring Weight

SWA can substantially increase drum and cable weight, affecting pulling and support requirements.

8. Ignoring Bending Radius

SWB may be more flexible, but every cable still has a minimum permitted bending radius.

9. Assuming Armour Determines Fire Performance

SWA and SWB do not define LSZH, flame retardancy or circuit integrity.

10. Choosing Armour Without Reviewing the Route

The correct armour is determined by the mechanical hazards and geometry of the actual installation.

What Should Buyers Include in an SWA or SWB Cable RFQ?

A request that states only “steel armored cable” can still leave important design questions unresolved.

A technically useful RFQ should consider specifying:

• Cable type
• Application
• SWA or SWB requirement
• Required mechanical protection
• Installation method
• Indoor or outdoor use
• Direct burial requirement if applicable
• Expected vibration
• Rodent protection requirement
• Required minimum bending radius
• Maximum cable outside diameter if restricted
• Required pulling tension
• Screening requirement
• Outer sheath material
• PVC, PE or LSZH requirement
• UV resistance
• Oil or chemical resistance where applicable
• Fire-performance requirements
• Operating temperature
• Grounding or bonding requirements
• Required cable gland interface
• Applicable standards
• Certificates and test documentation

This allows the manufacturer to select the armour construction according to a defined mechanical requirement rather than simply quoting the heaviest option available.

ETK Kablo SWA and SWB Cable Solutions

ETK Kablo manufactures SWA and SWB cable constructions for industrial instrumentation, signal and control, Ethernet and fiber optic applications.

Within instrumentation cables, SWA constructions provide robust protection for mechanically exposed process and infrastructure installations, while SWB options allow projects to combine additional mechanical protection with greater routing flexibility.

ETK Kablo’s armored Data/LAN range includes SWA and SWB constructions across Cat5e, Cat6 and Cat6A product families for industrial Ethernet installations where conventional structured cabling requires additional physical protection.

Fiber optic cable designs are also available with steel wire armour and steel wire braid for demanding infrastructure environments where optical fibers need protection against external mechanical stress.

Depending on the product family, SWA and SWB can be combined with different insulation, screening and outer-sheath systems, including PVC, PE and halogen-free materials.

The appropriate ETK construction should therefore be selected according to the cable’s transmission function, mechanical environment, required flexibility, installation method and fire or environmental specifications.

Frequently Asked Questions

What is the difference between SWA and SWB cable?

SWA uses galvanized steel wires applied helically around the cable and generally provides heavier mechanical protection. SWB uses interwoven steel wires and provides mechanical reinforcement with greater flexibility.

What does SWA mean?

SWA means Steel Wire Armour. It uses galvanized steel wires around the cable to protect against impact, crushing and other mechanical stresses.

What does SWB mean?

SWB means Steel Wire Braid. Fine galvanized steel wires are braided around the cable to provide mechanical protection while retaining greater flexibility.

Is SWA stronger than SWB?

SWA generally provides stronger protection against heavy mechanical loads and crushing. SWB provides a different balance by combining mechanical reinforcement with increased flexibility.

Is SWB more flexible than SWA?

Generally, yes. The braided steel structure can adapt more easily as the cable bends, making SWB useful where routing flexibility is important.

Is SWB cable suitable for movement?

SWB can tolerate bending and vibration better than many heavy SWA constructions, but it is not automatically a continuous-flex cable. Dynamic applications require a complete cable specifically designed for repeated movement.

Is SWA suitable for underground use?

SWA is frequently used in demanding underground installations because of its mechanical protection. However, the complete cable must also be designed for moisture, soil and environmental conditions.

Can SWB be used underground?

Yes, if the complete SWB cable construction is approved for the intended underground environment. Armour type alone does not determine burial suitability.

Does SWB provide EMI shielding?

Metallic steel braid can influence electromagnetic behaviour, but it should not automatically replace a dedicated electrical screen. Instrumentation and data cable shielding should be specified separately.

Does SWA provide EMI protection?

Steel wire armour can influence electromagnetic fields, but its primary purpose is mechanical protection. Dedicated foil or braid screens should be specified where signal shielding is required.

Which is better for oil and gas projects, SWA or SWB?

Both can be appropriate. SWA is often preferred for fixed routes requiring heavy mechanical protection, while SWB may be preferred where mechanical reinforcement and greater flexibility are both important.

Which is better for instrumentation cables?

The answer depends on the route. SWA provides heavier mechanical protection, while SWB provides more flexibility. Signal screening should be selected independently from armour type.

Which is better for Ethernet cables?

Both can protect industrial Ethernet cables. SWA is useful for heavy fixed routes, while SWB can be advantageous in complex or confined installations requiring additional flexibility.

Does SWA mean fire resistant?

No. SWA describes mechanical armour. Fire resistance, flame retardancy, LSZH performance and CPR classification are separate cable characteristics.

Does SWB mean LSZH?

No. SWB describes the steel braid. The cable can use PVC, PE, LSZH or another outer-sheath material depending on its design.

Conclusion

The choice between SWA vs SWB cable is fundamentally a balance between mechanical protection and flexibility.

SWA uses galvanized steel wires applied around the cable to create a robust armour layer. This makes it particularly suitable for fixed installations exposed to crushing, impact, rodents and substantial mechanical stress.

SWB uses an interwoven steel wire construction. It still reinforces the cable mechanically but allows greater flexibility, making it attractive where cable routes contain tighter bends, vibration or more complex installation geometry.

Neither armour type should automatically be considered superior.

SWA can create unnecessary weight and stiffness where heavy protection is not required, while SWB may provide less protection than a project needs in a severe mechanical environment.

Armour should also remain separate from other specification decisions. Signal shielding, fire resistance, LSZH performance, environmental protection, direct-burial suitability and electrical or optical performance must all be defined independently.

For engineers and purchasing teams, the best approach is therefore to identify the mechanical hazard first and then choose the armour structure that provides sufficient protection without unnecessary weight, rigidity or installation complexity.