Introduction to Armored Fiber Optic Cable? -Types & Features

Fiber optic cables are the backbone of the entire networking infrastructure. They are a superior choice to copper trunk cables, owing to the immunity to electromagnetic interference (EMI) and radio frequency interference (RFI). Fiber optic cables can send information over distances as large as metropolitan areas. Expense is one of the reasons for fiber optic cables not being widely used. Another reason is that fiber optic cables are fragile to environmental effects. Even with protective cladding, fiber optic cables are not safe from:

  • water penetration
  • rodents attacks
  • cracking due to excessive force.

This is where Armored fiber-optic cables come into the picture. It has a rugged corrugated steel armor or a durable material such as glass yarn or polyethylene around each fiber. This way, you provide more protection without sacrificing flexibility. You can install these cables in tight overhead spaces or underground ducts.

This article will explain the structure of an armored fiber optic cable, its types, and its application.

Structure of an Armored Fiber Optic Cable:

The above image shows the different layers of an armored fiber optic cable. A spiral steel ring outside a conventional fiber optic cable with an extra PVC protective layer on top. The yellow fibers are aramid yarn that is a fire retardant and blocks water from entering the fibers. Some manufacturers include specialized waterproof gel between the inner PVC protective layer and fibers. This sacrifices flexibility for ruggedness. The cross-sectional view of an armored fiber optic cable with an aramid yarn core is as below.

The armor around the fiber need not always be metallic. You can also have kevlar fibers, glass yarn, or polyethylene. Armored fiber optic cables with these materials are ideal for indoor usage. The reason being:

  • Less temperature stress
  • Low physical stress
  • Allow a small bend radius
  • Fire retardant.

The metal armor provides sturdiness without compromising the cable’s flexibility and is preferred more for outdoor installations.

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Types of Armored Fiber Optic Cable

Depending on the type of protective winding around the fiber optic cable, the armored fiber optic cable is available in two types:

  1. Interlocking
  2. Corrugated

Interlocking armored fiber cable has a protective sheath wrapped around the core in a spiral shape. It provides crush protection when laid in tight ducts or around heavy machinery.

Corrugated armored fiber cable uses corrugated metal tape folded around the core. The ridges of the tape discourage rodents from chewing on the cable. Hence, this cable type is ideal in areas with high rodent activity and in-between walls.

Why Should you Choose Armored Fiber Optic Cable?

There is only one difference between a standard fiber optic and an armored fiber optic cable. It is the protective layer around the core in an armored fiber optic. Due to this added protection, these cables can be installed in constrained areas or buried underground. These places are generally outdoors or cramped spaces with no ventilation. Here dust and water accumulate occasionally. The inner gel surrounding the fiber optic bunch keeps the dust and moisture from interfering with the transmission. The outer PVC cladding and the aramid yarn act as a fire retardant and prevents the cable from becoming a fire hazard. Finally, the internal metal or non-metallic sheath prevents cable damage from rodents or getting crushed under heavyweight. In a nutshell, the key features of an armored fiber optic cable are:

  1. Fire-resistant and rugged
  2. High transmission without interference
  3. Flexible with a slight bend radius.
  4. Water and dust protected
  5. Discourages rodent penetration

The only cons of buying armored fiber optics are the challenges faced in field terminations due to the armor layer. Yet, you can overcome it by opting for pre-terminated armored fiber cables.

Applications of Armored Fiber Optic Cable


  • Surveillance
  • Inter-department communication
  • Video Broadcast
  • High altitude telescope arrays
  • Network infrastructure backbone for a large industrial complex or campus
  • Telecommunication


  • Running optic fibers through underground conduits
  • Data Centers
  • Industry automation
  • Fire & Safety (Communicating between fire alarms)
  • Gigabit Ethernet

Wrapping Up

As you may have understood by now, armored fiber optic cables are one level above traditional fiber cables. They are a better choice when used in harsh operating conditions. You can buy spools of armored fiber cable for on-field termination or order pre-terminated patch cables from FalconTech. Armored fiber optic cables are available in multimode OM3, OM4, and single-mode OS2 variants.

Author Bio

Name: Allen Lu

Allen Lu is a sales manager at Falcon Technologies, Inc. We are the best seller for pre-terminated fiber optic cable assemblies in the United States.