Choosing Armored Cable

Armored Cable Types

Armored Cables

Our Cleerline SSF™ optical fiber is already extra durable due to the patented polymer coating at the glass level. However, some installations need even more robust protection for those optical fibers. In harsh environments, choosing a more protective cable construction is very important.

The most durable cables you can install are, of course, armored cables. These cable types incorporate an additional layer of aluminum or corrugated steel, providing extra crush resistance and allowing installation in difficult environments.

We currently offer two different types of armored cables: Aluminum Interlocking Armored and Armored Corrugated Steel. These cables provide the ultimate in protection, keeping optical fibers safe from impacts or industrious rodents. However, not all armored cables are alike. Aluminum Interlocking Armor is for indoor use only. Armored Corrugated Steel cable, conversely, is suitable for outdoor installations only.

Read on to learn more about these types of armored cables and how to choose the right construction.

Aluminum Interlocking Armored

Aluminum Interlocking Armored Cable

Need to protect cable indoors? Aluminum Interlocking Armored (AIA) is the cable you need. Unlike Armored Corrugated Steel cable, AIA is intended for indoor use only. While AIA does include water-blocking yarns, this cable is not intended for situations where standing water is a potential issue.

Aluminum Interlocking Armored is built with a spirally wrapped aluminum strip under the jacket. The cable also includes a subunit holding the optical fibers, plus additional strengthening aramid yarns.

One benefit of this cable is that, by virtue of being armored, it’s resistant to rodents. The spiral aluminum wrap also provides high crush resistance. AIA can also be installed without addition inner duct or conduit, which is a major labor savings. Note that this cable does have a larger outer diameter, at 11.6 mm and above, depending on the number of fibers.

Importantly, as Aluminum Interlocking Armored is intended for indoor use, it is rated accordingly. We currently stock AIA with a plenum outer jacket. Note if specifying these cables that they are rated OFCP (optical fiber conductive plenum). While optical fibers themselves are not conductive, the cable’s metal armor component does require notation for conductivity.

To recap, when is Aluminum Interlocking Armored needed?

  • Indoor applications only
  • High crush resistance required
  • Rodent resistance needed
  • Indoor installations without additional duct or conduit

Armored Corrugated Steel – Direct Burial

Armored Corrugated Steel Cables

As the name of this cable indicates, Armored Corrugated Steel (ACS) cable is intended for in direct burial applications outdoors. Under the outer layer of jacketing, a corrugated steel tube encases the cable’s secondary subunit, which holds the optical fibers. The whole cable is additionally packed with water blocking tape and strengthening aramid yarns (Kevlar ®).

ACS cable’s outer jacket is polyethylene, offering UV and moisture resistance. This is our most heavy-duty cable type. It’s also one of our larger cables, with a 9.0 mm outer diameter. As one might expect, due to the armored layer it is not as flexible as cables that do not incorporate steel. The armored layer does, however, allow this cable to handle being installed without conduit. The steel layer also prevents any enterprising rodents from trying to do their own fiber splicing.

ACS is not rated for indoor use. This is because the polyethylene jacketing is not intended for indoor applications and does not include a fire resistance rating (i.e. OFCP or OFCR).

So, when is Armored Corrugated Steel appropriate?

  • Outdoor applications only
  • High crush resistance required
  • Rodent resistance needed
  • UV resistant jacketing needed
  • Direct burial needed

Terminating Armored Cables


Both of our armored cables contain micro distribution subunits holding the actual fibers (multiple fibers within one subunit jacket). This means normal micro distribution termination considerations apply, i.e. you may want to consider installing a fanout kit or a breakout kit when terminating.

Watch a video showing preparation of our armored cable for termination.

To get to that subunit, however, you do need to get through the armor. We recommend having a cable slitting tool on hand, such as the SSF-ACS-Tool. This will allow you to cut into and remove the outer armored layer, exposing the subunit jacket below.

What if I need a rugged cable, but I don’t need armor?

If armored cables are beyond your installation needs, considering a cable like our Rugged Micro Distribution. This cable is meant to be installed in ducts or conduit indoors or outdoors, but it includes extra fiberglass yarns for strength. It’s also designed to provide additional rodent resistance. This style of cable is good compromise when you want additional cable protection, but armor is not required, or you need a fully nonconductive construction.

Choosing Armored Cable