Interlocked Armor is constructed of steel or aluminum tape spirally warped and formed around a cable to create the sheath or armor. As the name indicates, the tape is formed in a manner that each layer "interlocks" with the previous layer. Interlocking provides for flexibility in the finished product. Most of these cables comply with NEC Type MC (Metal Clad). A PVC jacket is commonly applied over the armor. Uses include direct burial, in tray and in free air.
Continuously Welded Corrugated Armor is constructed from aluminum tape that is formed longitudinally to the cable. The sheath is welded as the aluminum is formed to provide an impervious armor that prevents the entrance of water, gas and corrosive elements. A PVC jacket is commonly applied over the armor. Uses include AC drive power cable, and NEC Type MC-HL for use in Class 1, Division 1 hazardous locations. Used extensively in the paper, oil, and gas industries.