International standards
World-class quality assurance

Participate in multiple overseas projects

Participate in multiple overseas projects

British brand
Zero rejection from global consultants

Extensive experience in overseas project submission

Extensive experience in overseas project submission

Perfect combination of creativity and technology
Each cable is made as per demand

Special cable customization service

Special cable customization service
  HomeTechnical LibIntroduction to armored forms

Introduction to armored forms

Armored Cable Selection Guide

  1. Steel Tape Armor (STA)

    • Construction: Two-layer galvanized steel tapes helically wound with opposite directions

    • Key Properties:

      • Superior crush resistance (withstands up to 2500N/100mm)

      • Bending radius ≥12× cable diameter

      • Typical thickness: 0.2-0.8mm (IEC)

    • Applications:

      • Direct burial installations

      • Tunnels with potential rockfall

      • Industrial floors with vehicle traffic

  2. Steel Wire Armor (SWA)

    • Construction: Galvanized steel wires (Φ0.8-3.15mm) in single layer

    • Key Properties:

      • Tensile strength ≥350N/mm²

      • Bending radius ≥10× cable diameter

      • Zinc coating ≥40g/m² (BS standard)

    • Applications:

      • Vertical risers (supports self-weight)

      • Aerial spans ≤50m

      • Mining drag applications

  3. Steel Wire Braid (SWB)

    • Construction: Interwoven galvanized steel wires (Φ0.2-0.4mm)

    • Key Properties:

      • Shielding effectiveness ≥60dB (100MHz)

      • Bending radius ≥8× cable diameter

      • Typical coverage: ≥80% surface area

    • Applications:

      • Mobile equipment connections

      • EMI-sensitive environments

      • Oilfield drilling cables

Special Case: Single-Core Cable Armor

  • Material Requirement: Aluminum armor mandatory

  • Technical Reasons:

    1. Prevents eddy current losses (steel causes ≈5% power loss at 50Hz)

    2. Limits temperature rise (ΔT ≤30K under full load)

    3. Maintains impedance balance (R±jX variation <3%)

Standards Comparison

Parameter IEC 60502-2 BS 6724
Steel Wire Optional Galvanizing Mandatory Zn Coat
Minimum Diameter 0.8mm 0.9mm
Tensile Test 150N/mm² 350N/mm²
Corrosion Test 72h salt spray 144h salt spray

Selection Methodology

  1. Mechanical Stress Analysis:

    • Crushing forces → Choose STA

    • Tension loads → Choose SWA

    • Flexing requirements → Choose SWB

  2. Environmental Factors:

    • Corrosive atmospheres: Galvanized SWA (BS standard preferred)

    • Electromagnetic interference: SWB with ≥85% coverage

    • Temperature extremes: Aluminum armor for >90°C operation

Industry Trends

  • Composite armor (steel tape + aramid yarn) gaining popularity for:

    • 30% weight reduction

    • 40% improved flexibility

    • Equivalent mechanical protection

This technical breakdown provides engineers with the essential criteria for selecting appropriate cable armor based on project-specific mechanical, electrical, and environmental requirements.